薪酬作为一种重要的( )，可以调节劳动力在社会各地区、各部门和个企业之间的流动。A

下列化学反应中，属于化合反应的是（　　）

A．4P+5O₂

点燃  .

2P₂O₅

B．Fe+CuSO₄═FeSO₄+Cu

C．CaCO₃

高温  .

CaO+CO₂↑

D．Na₂CO₃+Ca（OH）₂═CaCO₃↓+2NaOH

根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多

余选项。

— May I help you, sir?

—  1 It's my watch. I brought it in to be repaired but now I have lost the receipt.

—Lost the receipt?   2  

— Can't I just describe the watch to you?

—   3  Only the manager can help you but he left a minute ago.

— Oh, dear. I think it was the manager who served me.

— Just a moment.  4  

— This time last week, during my lunch hour.

— And was your watch a small gold one?

— Yes, that is right.  5  

— Because your receipt is still here. You dropped it when you left. The manager shouted

       but you didn't hear.

A. What do you know about my watch?

B. When did you bring the watch in?

C. I hope so.

D. How did you know?

E. I'm sorry, I can't.

F. I'm afraid not.

G. Oh, dear. That is too bad.

As a photographer he always has his camera ready _______ he sees something that might make a

good picture.[ ]

A. so that

B. as long as

C. in case

D. only if

时间知觉可以借助的线索包括（）。

A.钟表提供的信息

B.四季的变化

C.生理活动的周期性变化

D.情绪的变化

按塑料用途分为（）、工程塑料和特种塑料三大类。