电能计量装置接线检查时,需要准备的材料包括( )。

A. 多股铜芯绝缘导线
B. 单股铜芯绝缘导线
C. 单股铝芯绝缘导线
D. 多股铝芯绝缘导线

电能计量装置安装时接线盒出线端导线接线应( )。

A. 只拧紧下面螺钉
B. 先拧紧上面螺钉,后拧紧下面一颗螺
C. 先拧紧下面螺钉,后拧紧上面螺钉
D. 只拧紧上面螺钉

Fill in the blanks with the proper forms of the verbs in the brackets.1. Politics _____ (be) much more difficult than physics.

2. Statistics __________ (suggest) that the population of this country will be doubled in ten years’ time.

3. The United Nations _____ (be) an international organization to maintain world peace and security.

4. The surroundings of animals _____ (be) worsen.

5. There _____ (be) a pair of scissors in the bottom drawer.

6. My savings __________ (amount) to $2,000.

DSA系统的机架按安装方式分可分为那些？

A. 落地式
B. 悬吊式
C. 镶入式
D. 贴墙式

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