问题 单项选择题

右图是一个圆柱体棱镜的截面图,图中E、F、G、H将半径OM分成5等份,虚线EE1、FF1、、GG1、、HH1、平行于半径ON,ON边可吸收到达其上的所有光线.已知该棱镜的折射率n=,若平行光束垂直入射并覆盖OM,则光线()

A、不能从圆弧射出

B、只能从圆弧射

C、能从圆弧射

D、能从圆弧射出

答案

参考答案:B

阅读理解

根据短文,判断正(T)误(F)

     You may ride on your bicycle in a rush to get to school every morning. You may also watch taxis move

their way slowly through traffic jams. No matter where you are, all big cities around the world have traffic

jams these days.

      In London, people like to take the "underground", also called the "tube". The city has the oldest and most

complicated underground railway system in the world and it is the pleasure of many Londoners. The tube is

normally the quickest and easiest way of getting around London. In London, you are never far from a tube

station.

     New York is famous for its yellow cabs (出租车). They serve as a quick and easy way of getting across

Manhattan. But, with over 12.000 yellow cabs in the Big Apple, (纽约别称) they are also a lot of traffic jams. 

     Since 1873 when the first cable car started public service, the slow and noisy vehicle has been a sign of

San Francisco. But there are no such symbols in Los Angeles. The city's public transportation is terrible. It

can take hours to get across town by bus.

( )1. All big cities around the world have traffic jams everywhere.                     

( )2. Londoners like to take the tube because it's quick and easy to get around the city.

( )3. You can hardly find a tube station in London because its railway system is too old.

( )4. There are no traffic jams in New York because of its famous yellow cabs.          

( )5. The slow and noisy vehicle is a symbol of San Francisco. So it is in Los Angeles. 

选择题