按照下面各题的汉语意思用英语完成句子，词数不限

1. 别让孩子们影响你.

    ____________________ let the children ____________________ you.

2. 张老师总是鼓励我们尽可能多讲英语.

    Mr Zhang always ____________________ English as often as possible.

3. 他们将开个会来讨论这个问题.

    They will ____________________ a meeting to discuss this problem.

4. 我们要每天浇花.

    The flowers ____________________ every day.

5. 在美国绝大部分农活是机器做的.

    Most of the farm work ____________________ in the USA.

在一些热交换器中，选用饱和器水蒸汽做加热热源，有何优点？