若函数f（x）=α2-cosx，则f′（x）=（ ） A．sinx B．cosx

根据句意填词。

1. Who do you often talk ______?

2. My pen is broken. May I ______ yours?

3. Math is too ______. I don't want to learn it.

4. There is ______ wrong with my watch. Can you mend it for me?

5. We must go ______ the road carefully. The traffic is heavy.

6. He lives in a big house ______ a small garden.

7. My home is far ______ my school. So I go to school by bus every day.

8. Sunday is the ______ day of the week.

9. My mother is ill , I have to look ______ her at home.

10. If you want to travel to Japan, you can go ______.

下列哪项指标阳性表明乙型肝炎病情为活动性（）

A.抗-HBs

B.抗-HBc

C.HBeAg

D.HBsAg

E.抗-HBe

如图所示，弹簧秤下挂着一重物A，烧杯中盛有溶液B，试根据要求回答下列问题：

（1）若A为铁块，B为稀硫酸，则将A放入B中，过一会，弹簧秤的读数将（填“变大”、“变小”或“不变”，下小题同）       ，反应的化学方程式为       ；

（2）若A为铁块，B为硫酸铜溶液，则将A放入B中，过一会，弹簧秤的读数将      ，反应的化学方程式为                     。

咨询工程师的项目管理是根据业主的委托，为寻求解决工程项目的( )的最佳途径提供的智力服务。

A．实际问题

B．决策问题

C．施工问题

D．设计问题