设A、B是非空数集，定义：A⊕B={a+b|a∈A，b∈B}，若A={1，2，3}，B={4，5，6}，则A⊕B的非空真子集个数为（　　）

A．64

B．32

C．31

D．30

完成句子，使改写后的句子完整，并与原句的意思相符，每个空格只准填一个单词。

1．It will be quite a windy day tomorrow. 

                                be a                           tomorrow.

2．There is something wrong with the computer now.

      The computer                          now.

3．People in the US can't drink beer or wine before they reach 21. 

      People younger than 21                                                      drink beer or wine.

4．Have you found the missing necklace?

      Have you found the necklace                           missing?

5．I'm going to make an early start so that I will catch the first train.

      I'm going to                                                     the first train.