听下面一段独白,回答以下小题。
8. What happens when you rub a balloon against your hair?
A.It gets sticky. |
B.It becomes positively charged. |
C.It picks up extra electrons and becomes negatively charged. |
9. Why does the negatively charged balloon stick to the wall?
A.Because the wall is also negatively charged. |
B.Because opposites attract. |
C.Because the wall becomes positively charged. |
10. What is the invisible force mentioned in the speech that causes the balloon to stick to the wall?
A.Magnetism. |
B.Static electricity. |
C.Gravitational pull. |
11. What term is used to describe the process of the balloon picking up extra electrons?
A.Magnetization. |
B.Electronization. |
C.Ionization. |
12. What is the main idea behind the explanation of static electricity in the speech?
A.Balloons sticking to walls. |
B.Rubbing objects together. |
C.Positive charges in the air. |
13. What happens to the balloon after it picks up extra electrons?
A.It becomes neutrally charged. |
B.It becomes positively charged. |
C.It becomes negatively charged. |
14. What does the speaker compare static electricity to in the speech?
A.Magic. |
B.Lightning. |
C.Magnets. |