根据首字母及句意补全单词。

1. Jack is going to be a computer p            after he learns the computer science well.

2. It's hot here.  Let's look for s          cool.

3. Bill Gates is a r           man. He has lots of money.

4. Brown is a college student, and he has a p         job in a shop.

5. Jack doesn't live here now. He m         to London last year.

口腔从外向内建立了多层次防护屏障，它们是（）.

A.唾液屏障

B.黏膜物理屏障

C.免疫细胞屏障

D.免疫球蛋白屏障

E.口腔耐受性