下列关于质点的说法，正确的是( ) A．原子很小，所以可以当作质点 B．研究和观

用所给词的适当形式填空。

1. He _____ (go) to school by dike every morning. But this morning he _____ (go) by bus.

2. "Do you like _____ (drink) tea?""Yes,I do."

3. I'm sorry. I can't. I have to _____ (help) my mom.

4. There _____  (not be) any bread at home yesterday.

5. Tom _____ (have) no time last Sunday. He _____ (visit) his friends next Sunday.

6. Please tell him _____ (wash) his hands before supper.

7. The bus _____ (stop) already. Let's get off.

8. Doing morning exercises _____ (be) good for you.

9.  Tom's brother _____ (be) good at soccer.

10.  Finally he asked people to stop _____ (talk).

左旋多巴治疗帕金森病的机制是（）

A.激动中枢M受体

B.补充纹状体中DA的不足

C.减少NA的再摄取

D.抑制脑内DA的降解

E.阻断DA受体

"美丽地描绘一副面孔"与"一副美丽的面孔"分别指的是（）。

A．自然美与艺术美

B．艺术美与自然美

C．自然美与艺术美

D．艺术美与现实美

在一定的社会背景下发生的促使个体社会化和社会个性化的实践活动就是( )。

A．教育
B．教学
C．管理
D．科研

治疗过敏性休克应首选（）

A.去甲肾上腺素

B.地塞米松

C.肾上腺素

D.多巴胺

E.阿托品