用适当的介词填空。

1. He climbed up to the top of a large rock, ______ where he got a good view.

2. The painting ______ which I looked was painted by Vincent Van Gogh.

3. The pen ______ which she wrote that book can now be seen in a museum.

4. The little creature (生物) ______ which scientists are interested is known as ET.

5. The film ______ which I fell asleep was very boring.

6. The gun ______ which he was shot was never found.

7. Please give me the reason ______ which you were late this time.

8. He remembers the day ______ which his father died. He was only ten years old at that time.

9. The girl ______whom you talked at the meeting is a college student.

10. The people ______ whom the man spoke weren't listening.

如图所示，一段下端散开，整体呈电中性（不带电荷）的塑料捆扎绳，用清洁干燥的手握住，自上而下地捋几次后，则下列说法中正确的是

A．一部分塑料带正电，另一部分塑料带负电，整个塑料绳仍呈现电中性

B．整个塑料绳不会带电

C．只是因为摩擦生热，使塑料绳受热变形呈散乱状态

D．手与塑料绳间发生电荷转移，使每根塑料绳带同种电荷而相互排斥散开