单选题A user is experiencing headaches and motion sickness symptoms when using their new computermonitor. Which of the following can a technician adjust to help the user?（）A Privacy filterB Refresh rateC Use a digital signalD Brightness

隐症现象（masking of symptom）

A user reports that a network printer will not print, however, other users are not experiencing any problems. The user has rebooted their computer twice and it is still not printing. Which of the following should the technician check?（）

After removing several obsolete programs from a PC, a user is experiencing slower than usuallyprocessing times. Which of the following would be the BEST way to speed up the processing? （）

The exhaust ports of a diesel engine using the cross-flow scavenging method are opened and closed by the （）

The linear motion of a diesel engine piston is converted to the rotary motion required to drive gears, propeller shafts, and generators by the （）.

A user complains that a computer monitor is experiencing a jitter. Replacing the monitor and video card does not fix the problem. Which of the following could be causing the problem？（）

As the designated rudder angle is being achieved, as a result of the original command input, the steering gear follow-up mechanism is（）

发病期（symptom appearance）

A user is experiencing headaches and motion sickness symptoms when using their new computermonitor. Which of the following can a technician adjust to help the user?（）

Directions:In this section, there is one passage followed by a summary. Read the passage carefully and complete the summary below by choosing a maximum of three words from the passage to fill in the spaces 76-80. Remember to write the answers on the Answer Sheet.　　Questions 1-5 are based on the following passage.　　Headaches are a big problem. But they are not just a problem for the person suffering from the headache. They are a problem for society as well. Each year, millions of people suffer from severe headaches that keep them from doing their jobs. In fact, according to one estimate, headaches cost individuals and businesses more than $50 billion each year! This is one of the reasons research into headaches has become a worldwide effort.　　Although he did not know much about how headaches work, Hippocrates was the first doctor to find a way to treat them. Before 400 B.C., Hippocrates discovered that the bark from willow trees was useful in treating pain. He made a white powder from the tree’s bark and gave it to his patients.　　Hippocrates did not know it, but he was actually prescribing a natural chemical in willow bark called salicin. When a person eats salicin, the chemical is changed inside her or his body into salicylic acid. It turns out that salicylic acid is good for stopping pain, including headache, but it is bad for a person’s stomach. In the 1800s, a chemist in Germany changed the acid’s form a little to make it easier for people to take. This new form of the chemical was called acetylsalicylic acid, commonly known as aspirin today.　　Aspirin was used throughout most of the 1900s to treat headaches, but doctors had little idea about what really caused headaches. When doctors know the cause of a disease, they can find better ways to treat it. Therefore, as medical technology developed, doctors began to use the technology to learn more about the human brain and about headaches.　　Currently, doctors classify headaches into two general types: primary and secondary. A primary headache is a condition suffered as only the headache itself. On the other hand, a secondary headache is one caused by another condition. For example, someone who catches the flu may suffer from headaches along with other symptoms of the illness. Flu headaches are thus secondary headaches.　　For primary headaches, doctors have determined three possible causes. One kind of primary headache is caused by stress. Doctors usually call these tension headaches. Such headaches are characteristically felt on both sides of the head as a dull, steady pain.Another kind of primary headache is the migraine headache. Doctors believe these headaches are caused by reduced flow of blood to certain parts of the brain. A migraine sufferer usually feels intense pain on one side of the head. The sufferer also becomes sensitive to light and noise. If the migraine is severe, the sufferer may vomit repeatedly.　　The third kind of primary headache is known as the cluster headache. Cluster headaches typically occur around the same time each day for weeks or months at a time. The person suffering from this kind of headache usually feels pain on one side of her or his head, and the pain is centered around one of the person’s eyes. Doctors do not know much at present about cluster headaches, but they seem more common among men and could be related to alcohol or other things that affect a person’s blood flow.　　Using computers and more advanced medical equipment, doctors continue to learn more about what happens in the brain before and during headaches. Especially in the case of migraines, some doctors believe they have found the part of the brain that sets off the reaction for severe attacks. With this new insight into brain processes, doctors hope new ways will be discovered for stopping disabling headaches before they begin.　　Summary:　　Doctors knew a long time ago that the 　1　from the willow trees could help people who felt pain. Hippocrates was the first doctor to change organic material into a powder and give it to his patients. But it was not until the 1800s that this natural drug was altered and became known as 　2　.　　With the help of technology, doctors have now gained detailed insight into how the brain works and what happens when a person suffers from a headache. Through this research, headaches have been 　3　primary and secondary headaches. There are three types of primary headaches: tension, migraine, and cluster headaches. Although not much is known about cluster headaches, doctors have been able to determine some of the things that 　4　During a migraine attack, the sufferer may become 　5　and noise.

You have a firewall enforcer protecting resources in a data center. A user is experiencing difficulty connecting to a protected resource.Which two elements must exist so the user can access the resource?（）

The projection on a shaft designed to change circular motion into up and down or back and fore motion is called （）.

A technician just installed an antivirus suite on a workstation. It is kept up-to-date and has recently scanned the system. A day later the user reports slower response times than usual. Which of the following is the user MOST likely experiencing?（）

Here, so profligate has its use become the air conditioner is almost ______ the automobile of the national tendency to overindulge in every technical possibility, to use every convenience to such excess that the country looks downright coddled.