问题 选择题

依据已知的数据,可以计算出地球质量的是(万有引力常量G已知)[    ]

A.月球绕地球运行的周期及月球到地球中心的距离

B.地球“同步卫星”离地面的高度

C.人造地球卫星在地面附近的运行速度和运行周期

D.地球绕太阳运行的周期及地球中心到太阳中心的距离

答案

AC

,可知,在B中不知地球半径,在D中只能求出太阳的质量.

单项选择题 A1/A2型题
阅读理解

阅读理解

     It is often considered that the schoolyard is where bullies(欺负)go to make other kids a miserable

school life, but a new study suggests that classrooms are another popular place.

     The study,presented recently at the American Public Health Association's yearly meeting in

Philadelphia,is based on the results of the research from more than 10,000 middleschool students who

answered questions online.

     Of those researched,43%said they'd been physically bullied within the last month.A bit more than half

said they'd been laughed at in an unfriendly way, and half reported being called hurtful names.About

onethird said groups had excluded (排斥)them to hurt their feelings.28% said their belongings had been

taken or broken;21%said someone threatened to hurt them.According to the results,twothirds of the

students said they'd been bullied in more than one way over the previous month.

     The study authors mentioned that 8% of the students who answered said they'd missed school at least

once during the school year because of fear of being bullied. 25% said they'd taken other actions,such

as missing recess(课间),not going to the bathroom or lunch,missing classes,or staying away from some

area of the school to escape from experiencing a bully.

     Bullies did too much to the school life.

1. Bullies can happen in the following places except________.

A. schoolyards  

B. classrooms

C. bathrooms  

D. teachers' offices

2. Which of the following is the best title?

A. Bad School Life  

B. Fear at School

C. Bullies at School 

D. School Problems

3. Some students might ________ to protect themselves from bullies.

A. leave the school

B. go for lunch

C. hurt others

D. break others' belongings

4. The writer feels ________ about bullies at school.

A. excited  

B. disappointed

C. worried  

D. puzzled