如图所示，在O点正下方有一个具有理想边界的磁场，铜环在A点由静止释放向右摆至最高

以上是一份针对学生的musical habits的调查问卷及结果。请根据问卷选择最佳答案。

MUSICAL HABITS QUESTIONNAIRE                                                                                 Yes   No
1. Do you like listening to music?	18	2
2. What kind of concerts do you prefer?   Pop concerts   Rock concerts Never go to concerts	8 4	8
3. Do you play a musical instrument?	14	6
4. How often do you play your instrument?   0～3 hours per week   3～6 hours per week   Never play any instruments	10 4	6
5. What instrument is your favourite? Guitar   Piano   Violin   No favourite instruments	7 5 2	6

小题1:We asked ______ students about their musical habits.

A．eight

B．ten

C．eighteen

D．twenty

小题2:How many kinds of instruments are mentioned?

A．Two

B．Three

C．Four

D．Five

小题3:Most students like _______.

A．playing the violin	B．going to rock concerts
C．listening to music	D．playing the piano

小题4:Which of the following is NOT RIGHT according to the questionnaire?

A．Six students like the guitar best.

B．Ten students play the instrument 0～3 hours per week.

C．Six students never play any instruments.

D．Four students prefer rock concerts.