At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems

Which of the following statements is TRUE according to the passage?___________

A.Oceanic salinity has great effect on sea life
B.Many factors combine to cause changes in oceanic salinity
C.The movement of the water is related to the amount of salt
D.The temperature of the water has much to do with the oceanic salinity

__________My room gets very cold at night.

A.So is mine
B.So does mine
C.So mine is
D.So mine does

At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.

Some scientists think there may have been life on the Mars in the past because__.

A.there is no life there now
B.there is a large amount of water at the poles
C.the Mars may be able to support life in the future
D.conditions may have been similar to those on the Earth

共用题干
第一篇

Water Resources on the Earth

The second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.
The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.

Liquid water only exists________.
A: in the center of the earth
B:on the surface of our planet
C:in the coastal areas of the earth
D:in a very narrow range of temperatures

共用题干
A Record-Breaking Rover
NASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.
“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.
He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”
The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.
Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.
During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.
The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.
Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet.

Opportunity is a record breaking rover in the sense of________.
A: how long is has stayed in space
B: how far it has traveled
C: how much investment it has involved
D: how many facilities it has been equipped with

共用题干
A Record-Breaking Rover
NASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.
“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.
He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”
The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.
Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.
During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.
The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.
Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet.

What does John Callas say about Opportunity's long distance travel?
A: It hasn't met scientists' expectation yet
B: It hasn't been appreciated appropriately
C: It is secondary to what has been discovered
D:.It is what scientists have been aiming at

At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.

There could be life on the Mars in the future if

A.it supported life in the past
B.certain gases are used to cool the planet
C.the atmosphere can be heated enough to grow simple plants
D.the planet's volcanoes become as active as they were in the past

At the first sight the planet Mars does not appear very welcome to any kind of life．It has very little oxygen and water,the temperature at night is below-50~Cand winds of 100 miles per hour cause severe dust storms．However,the surface of the planet seems to show that water flowed across it some time in the past,and it is believed that there is enough ice at the poles to cover the planet with water if it melts．Although there is no life on the Mars now,some scientists think that there may have been some form of life long time ago．At that time,the planet had active volcanoes;the atmosphere was thicker and warmer;and there was water．In fact,in some ways the Mars may have been similar to the Earth,where life exists.
Some people believe that the Mars could support life in the future if the right conditions were produced．The first step would be to warm the planet using certain gases which trap the Sun's heat in the planet's atmosphere．With warmth,water and carbon dioxide(二氧化碳),simple plants could begin to grow．These plants could slowly make the Mars more suitable for living．It is estimated that the whole process might take between 100,000 and 200,000 years．In the meantime,people could begin to live on the planet in special closed environments．They would provide a lot of useful information about conditions on the Mars and the problems connected with living there.

The author's attitude towards the possibility of life on the Mars in the future is__.

A.doubtful
B.positive
C.negative
D.uninterested

共用题干
第一篇

Water Resources on the Earth

The second most important constituent（构成成分）of the biosphere（生物圈）is liquid water. This can only exist in a very narrow range of temperatures,since water freezes at 0℃and boils a 100℃．Life as we know it would only be possible on the surface of a planet which had temperature: somewhere within this narrow range.
The earth's supply of water probably remains fairly constant in quantity.The total quantity of water is not known very accurately,but it is about enough to cover the surface of the globe to a depth of about two and three-quarter kilometers.Most of it is in the form of the salt water of the oceans一about 97 percent. The rest is fresh.But three-quarters of this is in the form of ice at the poles and or mountains and cannot be used by living systems until melted.Of the remaining fraction,which h somewhat less than one percent of the whole.There is 10—20 times as much stored underground water as there is actually on the surface.There is also a tiny,but extremely important fraction of the water supply which is present as water vapour in the atmosphere.
Water vapour in the atmosphere is the channel through which the whole water circulation（循环） of the biosphere has to pass.Water evaporated（蒸发）from the surface of the oceans,from lakes and rivers and from moist（潮湿的）earth is added to it. From it the water comes out again as rain or snow,falling on either the sea or the land. There is,as might be expected, a more intensive evaporation per unit area over the sea and oceans than over the land,but there is more rainfall over the land than over the oceans and the balance is restored by the run off from the land in the form of rivers.

The word"fraction"in the second paragraph means________.
A:a large area
B:a very small amount
C:an important system
D:a major source of information

共用题干
A Record-Breaking Rover
NASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.
“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.
He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”
The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.
Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.
During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.
The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.
Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet.

Which of the following statements is true of Opportunity?
A: It will come back to earth soon.
B: Another rover will be sent to replace it.
C: It is travelling to another major investigation site.
D: It will work with other rovers exploring Mars.

共用题干
A Record-Breaking Rover
NASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.
“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.
He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”
The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.
Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.
During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.
The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.
Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet.

It can be inferred from the last paragraph that＿________.
A: experts know how far Opportunity will make in Mars
B:.reseachers are working on sending many more humans to Mars
C: Mars's ancient environment might be exposed with the help of Opportunity
D: Opportunity is supposed to collect clay minerals from Marathon Valley

共用题干
A Record-Breaking Rover
NASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.
“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.
He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”
The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.
Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.
During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.
The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.
Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet.

One of the objectives of sending Opportunity and Spirit is to＿________.
A: collect soil and send back to Earth
B: develop multinational space exploration
C:.test how well solar-powered rovers work in outer space
D: look for the possible presence of life