单选题16. Date d = new Date（0L）；  17. String ds = “December 15， 2004”；  18. // insert code here  What updates d‟s value with the date represented by ds？（）A18. d = df.parse（ds）；B18. d = df.getDate（ds）；C18. try {  19. d = df.parse（ds）；  20. } catch（Pars

下列表达式中，运算值为日期型的是______。

A．YEAR(DATE())

B．DATE()-{12/15/99}

C．DATE()-100

D．DTOC(DATE())-"12/15/99"

在下列程序的空白处，应填入的正确选项是（ ）。 Import java．io．*； Pulilc class ObjectStreamTest{ Publilc static void main(string args[])throws IOEx- ception{ OhiectOutputStream os=new OhjectOutputStream (new FileOutputStream("serial．bin"))； Java．util．Date d=new Java．util．Date； Oos (d)； ObjectInputStream is= new OhjectlnputStream(new FileOutputStream("serial． bin"))； try{ java．util．date restoredDate= (Java．util．Date)ois．readObject； System．out．println ("read object back from serial．bin file：" +restoredDate)； } Catch(ClassNotFoundException cnf){ System．out．println("class not found")； } }

A.WriterObject

B.Writer

C.BufferedWriter

D.writerObject

A.var k = new Date( );

B.Date k = new Date( )

C.var k = new date( )

D.以上说法均不对

（ 11 ）请在下列程序的空白处，填上适当的内容：

Import java. awt. *;

Import java. util. *;

Class BufferTest{

Public static void main(string args[])

Throws IOException{

FileOutputStream unbuf=

new FileOutputStream( “ test.one ” ) ;

BufferedOutputStream buf=

new 【 11 】 (new FileOutputStream( “ test.two ” ));

System.out.println

( “ write file unbuffered: ” + time(unbuf) + “ ms ” );

System.out.println

( “ write file buffered: ” + time(buf) + “ ms ” );

}

Static int time (OutputStream os)

Throws IOException{

Date then = new Date();

for (int i=0; i<50000; i++){

os.write(1);

}

}

os.close();

return(int)(()new Date()).getTime() - then.getTime());

}

下列程序将Date对象写入文件file42.txt中，选择正确的语句填入下列程序中的横线处。 package ch1； impbrt java. io. *； import java. util. *； public class ex42 { static String fileName = "ch1\\file42.txt"; static Date date = null; public static void main(String[] args) { date = new Date(); try { FileOutputStream fos = new FileOutputStream(file Name); ObjectOutStream os = new ObjectOutputStream(fos); oos.______; oos.close(); fos.close(); System.out.println(date.toString()); } catch(Exception e) { System.out.println(e.getMessage()); } } }

A．writeObject()

B．writeObject(date)

C．write(date)

D．writeByte(date)

A.Date()

B. Date(int year, int month, int date)

C.Date(String s)

D.Date(long date)

A. alert(new Date(2011 , 12 , 25).getDay());

B. alert(new Date(2011 , 12 , 25 , 5).getDay());

C. alert(new Date(2011 , 12 , 25 , 5 , 5 , 9).getDay());

D. 以上三个结果都正确

材料：

A Passenger Ship Safety Certificate shall be issued for a period not exceeding 12 months．A Cargo Ship Safety Construction Certificate，Cargo Ship Safety Equipment Certificate and Cargo Ship Safety Radio Certificate shall be issued for a period specified by the Administration which shall not exceed five years．

An Exemption Certificate shall not be valid for longer than the period of the certificate to which it refers.

（i）When the renewal survey is completed within three months before the expiry date of the existing certificate，the new certificate shall be valid from the date of completion of the renewal survey to：

（1）for a passenger ship，a date not exceeding 12 months from the date of expiry of the existing certificate；

（2）for a cargo ship，a date not exceeding five years from the date of expiry of the existing certificate；

（ii）When the renewal survey is completed after the expiry date of the existing certificate，the new certificate shall be valid from the date of completion of the renewal survey to：

（1）for a passenger ship，a date not exceeding 12 months from the date of expiry of the existing certificate；

（2）for a cargo ship，a date not exceeding five years from the date of expiry of the existing certificate；

（iii）when the renewal survey is completed more than three months before the expiry date of the existing certificate，the new certificate shall be valid from the date of completion of the renewal survey to：

（1）for a passenger ship，a date not exceeding 12 months from the date of completion of the renewal survey；

（2）for a cargo ship，a date not exceeding five years from the date of completion of the renewal survey．

问题：

The valid period of an Exemption Certificate for Cargo Ship Safety Equipment Certificate shall be ________．

A.longer than five years

B.shorter than five years

C.longer than 12 months

D.shorter than 12 months

When the renewal survey is completed within one month before the expiry date of the existing Cargo Ship Safety Construction Certificate，the new certificate shall be valid ________．A.from the date of completion of the renewal survey to a date not exceeding 12 months from the date of expiry of the existing certificate

B.from the date of completion of the renewal survey to a date not exceeding five years from the date of expiry of the existing certificate

C.from the date of expiry of the existing certificate to a date not exceeding 12 months from the date

D.from the date of expiry of the existing certificate to a date not exceeding five years from the date

It can be concluded that the actual period of validity of a new Passenger Ship Safety Certificate is less than 12 months if the renewal survey is completed ________．A.4 months before its expiry date

B.3 months before its expiry date

C.2 months before its expiry date

D.after its expiry date

When the renewal survey is completed on a date which is 99 days before the expiry date of the existing Cargo Ship Safety Radio Certificate，the new certificate shall be valid ________．A.from the date of completion of the renewal survey to a date not exceeding 12 months from the date of expiry of the existing certificate

B.from the date of completion of the renewal survey to a date not exceeding five years from the date of expiry of the existing certificate

C.from the date of expiry of the existing certificate to a date not exceeding 12 months from the date

D.from the date of completion of the renewal survey to a date not exceeding five years from that date

请帮忙给出每个问题的正确答案和分析，谢谢！