问题 选择题
如图所示,白光垂直于等边三棱镜AB边进入三棱镜后射到BC边,并在BC边上发生全反射,若保持白光入射点位置不变,而将白光在纸面内缓慢逆时针转动,则最后从BC边射出的光是(  )

A.红光

B.白光

C.紫光

D.无法判断

答案

答案:C

阅读理解

Separate lives, similar dreams
As we know, some children live in the countryside, and some live in the city. Their lives are a little different, but they also have many of the same dreams.
 
In the countryside
In the city
Travel to school
On foot
By bus or car
Classroom facilities(设施)
Recorders and radios.
Multimedia classrooms, VCD, DVD, TVs, recorders, radios, loud-speakers.
Ways of learning
Classes only, without many reference books.
Many extra classes, tutor, lots of reference books.
Eyesight
Less than 45% are near-sighted.
About 75% are near-sighted.
After-class activities
Playing with balls.
English corners and other school clubs.
Homework
Homework can usually be finished at school.
Homework never ends.
Chores to do
Washing, cleaning, farming, looking after younger sisters or brothers, cooking.
Usually no chores.
Family members
Big families with three generations.
Small families with three members.
Ideal jobs
Teachers, drivers, scientists, nurses, secretaries.
Scientists, professors, doctors, computer programmers, managers, university presidents, the UN chief.
小题1: The survey was done among the ______ between in the countryside and the city.
A.teachers.B.students.C.parents.D.adults.
小题2:. About ______ of children in the countryside have good eyesight, but only ______ of children in the city have good eyesight.
A.45%,75%.B.55%,75%.C.55%,25%.D.45%,25%.
小题3: Which of the following is not included in the survey?
A.Ideal jobs.B.After-class activities.
C.Ways of learning.D.Results of tests.
小题4:. A classroom in the countryside often has ______ according to the survey.
A. records.            B. DVD.               C. TVs.                 D. loud-speakers.
小题5: Which of the following is WRONG according to the survey?
A.Children in the countryside often go to school on foot.
B.Children in the city often have too much homework to do.
C.Children in the countryside often have lots of chores to do.
D.Children in the city are difficult to find ideal jobs.
单项选择题