题目内容：

 

    The French submarine is called Le Triomphant, meaning“the winner”．The name of the British submarine is Vanguard，meaning“the leading position in an army”．It’s clear from the submarines’names that they were made for victory．  

    However，it was an accident，rather than a victory，that led these two submarines to recently make news headlines across the world．

    On February 16，Britain and France admitted that two of their nuclear—armed submarines，HMS Vanguard and Le Triomphant，collided while deep in the Atlantic in early February．Both submarines were on secret patrols(巡逻)and carrying nuclear arms when they collided．

    Le Triomphant had no idea that it had run into HMS Vanguard until several days later．The French navy at first believed that Le Triomphant had hit an“object，probably a container(集装箱)”．

    Investigations have begun to work out how such a collision could have happened．Both submarines are equipped with state-of～the—art(最先进的)technology that is supposed to find other submarines．Yet，neither submarine saw the other until it was too late．

    One idea being considered was that their anti-sonar(抗声纳)equipment，which hides submarines，was just too effective in hiding one from the other．  

    Submarines use sonar to sense what is in the sea near them．Sonar is a submarine’s ear．Many sea animals use sonar as well．Dolphins produce high-pitched(声调高的)clicks．when these clicks hit an object，some of the sound will echo(发出回声)back to the“sender”．By listening to the echo and working out the time it took before the echo came back，the dolphin can work out how far away the object is．

    There are two kinds of sonar：active sonar，which sends out signals，and passive sonar，which listens for signals with extremely sensitive microphones．

The two submarines were designed to be very quiet and as hidden as possible．because a submarine’s job description(工作职责)is not to be found．Many modern submarines do not use active sonar，only passive sonar．This makes it very difficult for a submarine to“hear”if another submarine is near．  

    Britain’s Ministry of Defense(国防部) has said the collision did not lead to any radioactive leaks(放射物泄漏)．The chance of a full nuclear explosion was almost impossible．However，experts say that if the walls of the submarines had broken，or a fire had been started，there could have been a major disaster．

    A senior British Navy source told The Sun newspaper that the possible consequences of such a collision were“unthinkable”．

    “It’s very unlikely there would have been a nuclear explosion．But a radioactive leak was a possibilitv．That would have been a national disaster．”he said．

1.What has made HMS Vanguard and Le Triomphant well known recently?  

  A、l heir names carried very positive meanings．．

  B、They collided in the Atlantic this February．

  C、They are both equipped with advanced technology．

  D、They are both nuclear—armed submarines．

2.What’s the probable reason for the accident?

  A、The two submarines were moving at a high speed．

  B、Their anti—sonar equipment was too effective．

  C、They were not equipped with active sonar．．

  D、The submarines were designed to be too quiet．  

3.Which of the following is the right order in which the dolphin senses the object’s position?

   a、The sound hitting the object．

   b、Producing high—pitched sound．

   c、The sound echoing back．

   d、Working out the time to come back．

   e、Receiving the sound．

  A、b一a—c—d—e   B、d—a—e—c—b   C、b—c—d—a—e   D、b—a—c—e—d

4.Which of the following is NOT true about the passage?  

A、Both of the submarines carried nuclear arms when they collided．

B、Many modern submarines do not use passive sonar so as to be as hidden as possible．

C、The collision may have caused a disaster if a fire had been started．

D、There would have been a nuclear explosion if the two submarines had collided harder．