防爆区的电机，照明应采用（），避免因接触不良、超负荷或过热而产生火花或着火。A、普通

—Where______my keys?  

—Sorry,______.       [ ]

A. is;  I don't know      

B. are; I don't know      

C. are; it's here      

D. is; it's here

句型转换。

1. They had fun in the park. (改为同义句)

    They                                                        in the park.

2. He is going to have a party next Sunday. (改为一般疑问句) 

                 he                                          a party next Sunday?

3. They are going to visit Beijing. (改为否定句)

    They _______ ________ ________ _______ Beijing.

4. Last year Mr Wang went to New York City. (就划线部分提问)

    _______ did Mr Wang _______ last year?

5. I often help parents do housework on Sundays. (改为同义句)

    I often ______ parents ______ housework on Sundays.

6. He does his homework in the evening. (改为否定句)

    He _______ _______ his homework in the evening.

7. He is ready for the Christmas. (改否定句)

    He _____ _______ _______ ______ the Christmas.

8. He didn't come here because he was ill. (就划线部分提问)

    _______ _______ he ______ here?

9. Jenny eats jam every morning. (用tomorrow morning 替换every morning)

    Jenny ______ _______ _______ _______ jam tomorrow morning.

10. I clean my room twice a week. (就划线部分提问)

      ______ _______ ______ you clean your room?

在检修现场空开（三相空开）上接一台零时使用的角向磨光机（电源220伏），以下电源线接法正确的是（）。

A、选择空开上两个相邻的接线螺钉分别接上角向磨光机的两根电线就可以用了。

B、选择空开上两个不相邻的接线螺钉分别接上角向磨光机的两根电线就可以用了。

C、从空开上的输出端接线螺钉中选择两个相邻的接线螺钉分别接上角向磨光机的两根电线就可以用了。

D、从空开上的输出端接线螺钉中选择一个接线螺钉接上角向磨光机的两根电线中的一根，然后将另外一根电线接到空开附近的零线接线柱上就可以用了。

我国在建设领域推行项目法人负责制、工程监理制、招标投标制和合同管理制，在这些改革中，核心内容是( )。

A．项目法人负责制
B．招标投标制
C．工程监理制
D．合同管理制

代用货币与信用货币的价值基础决定有什么不同？