在下列各句的空白处填入一个最恰当的单词，使句子意思完整，语法正确。

1.  It's a teacher's_________to teach the students well.

2.  You shouldn't worry about your problems. You should_________the challenges instead.

3.  Worrying about our problems can also_________the way we behave with our families.

4.  Tom and I are good friends.  I hope our_________will last long.

5.  All the villagers are looking for the_________boy in the mountains.

6.  Don't talk_________in the classroom. The students are studying.

施工现场的配电装臵是指施工现场用电工程配电系统中设臵的（）。

A、总配电箱

B、分配电箱

C、开关箱

D、机电设备