单词填空。

1. The doctor is _________ (执行) an operation now.

2. He expressed it in the _________ (形式) of music.

3. They started to play their own _________ (乐器) and write their own songs like

   a real band.

4. I gave up because I didn't have any _________ (自信心) in myself.

5. Increasing numbers of people are _________(敏感的) to pollen (花粉).

6. After the lunch we parted, so I didn't know what happened to him a_________.

7. The boy sings so well that he dreams of being a m_________ tomorrow.

如图所示，倾斜索道与水平面夹角为，当载人车厢与钢索匀加速向上运动时，车厢中的人对厢底的压力为其体重的1.25倍（车厢底始终保持水平）则车厢对人的摩擦力是体重的（  ）

A．倍

B．倍

C．倍

D．倍