词语辨析.

A. add up／add to／add up to

1. Five ____ seven makes twelve.

2. The pupils are too young to ____ these figures.

3. The amount of money he makes a month ____ more than 59 000 dollars.

B. calm／still／silent

4. After the storm the sea became ____ again.

5. Keep ____. I am taking a photo of you.

6. Don't keep ____ on bad behavior.

C. too much／much too

7. Never drink ____, for it is bad for your health.

8. The question is ____ difficult for me. Would you please help me out?

下列原子结构示意图代表的粒子属于金属元素的是（　　）

A．

B．

C．

D．