问题 选择题

某星球的半径为R,在其表面上方高度为aR的位置,以初速度v0水平抛出一个金属小球,水平射程为bR,a、b均为数值极小的常数,则这个星球的第一宇宙速度为(  )

A.

B.

C.

D.

答案

答案:A

题目分析:设该星球表面重力加速度为g,小球落地时间为t,抛出的金属小球做平抛运动,根据平抛运动规律得aR=  bR=v0t,联立以上两式解得g=,第一宇宙速度即为该星球地表卫星线速度,根据地表卫星重力充当向心力得mg=m,所以第一宇宙速度v=,故选项A正确。

阅读理解

Starting from April, 2010, you won’t be hearing the word “NBA” on sports programs on CCTV. Instead, sport host will give the full Chinese name when they refer to the NBA – National Basketball Association. You also won’t hear any other English abbreviations (缩略词) on CCTV’s Chinese programs, such as GDP (gross domestic product), or WTO (World Trade Organization). You will hear their Chinese translations.

CCTV received a notice from the State Administration of Radio, Film and Television telling it to avoid using English-language abbreviations in their reports to protect the “purity” of the Chinese language. A few other TV stations also received the notice.

Fu Zhenguo, an editor of People’s Daily, is one of the people who suggested the change. “Firstly, using English in a Chinese-speaking environment is against Chinese law,” he said. “Then, using English on Chinese TV programs is unfair to people who don’t understand English. What’s worse, it will have a bad language influence on kids and teenagers.”

A lot of netizens have criticized the move, saying that it will cause problems for them.

“I understand what CD, VCD and DVD mean when I hear them. But I won’t know what the TV programs are talking about if I hear those products’ full Chinese names,” a netizen wrote in a BBS post. Following the same post, another netizen wrote jokingly: “I’m not listening to my MP3 now. I’m listening to my Moving Picture Experts Group-1 Audio Layer 3 (动态影像专家压缩标准音频第三层面).”

小题1:What does the underlined word “purity” in the second paragraph mean?

A.纯正

B.高贵

C.时髦

D.潮流小题2:How many reasons did Fu Zhenguo list to show his support for the change?

A.1

B.2

C.3

D.4小题3:Some netizens went against the change because_______________.

A.the application of abbreviations will make Chinese popular.

B.the application of abbreviations will attract the youth.

C.the application of abbreviations will not simplify the understanding.

D.the application of abbreviations will not bring Chinese to an end.小题4:What can be the full name of CCTV mentioned in the text?

A.Close Closet Top Video

B.China Central Television

C.China Common Time Voice

D.Closed-Circuit Television

单项选择题