根据句意及单词首写字母完成句子。

1. The ice is very thick. Let's go s         .

2. The students are r         money for the poor.

3. Jack has been in the club s       two years ago.

4. Several s          have been skating for 2 hours.

5. D     the second World War, many European Jews came to Shanghai.

“远望”号航天测量船，通过发射和接收一种波。对“嫦娥一号”进行跟踪、测量与控制。这种波是 [ ]

A．红外线

B．紫外线

C．超声波

D．微波