若15以内的质数的平均数是M，则与N=10×M最接近的整数是______．

句型转换。

1. How's the weather today? (同义句转换)

    ________ the weather ________ today?

2. He is doing sports in the park. (对画线部分提问)

    ________ ________ he ________ in the park?

3. Tom bought a book about history last week. (否定句)

    Tom ________ ________ a book about history last week.

4. Sally has to clean the room every day. (改为一般疑问句)

   ________ Sally ________ to clean the room every day?

5. The old man doesn't want to do anything. (同义句转换)

    The old man ________ to do ________.

下列属于日本谈判选手信奉的谈判哲理的是（）

A、笑脸讨价还价

B、吃小亏占大便宜

C、放长线钓大鱼

D、抓关键人物

什么是远近效应？

复杂管路可分为（）、（）、（）等类型。

简述多方通信。