在我国企业中存在的三角债现象，本质上属于 ( )A．商业信用 B．银行信用 C．

句型转换。

1. It's cloudy today. (对划线部分提问) 

                is the weather             today?

2. I went to bed after I finished my homework last night. (同义句)

    I ______ go to bed ______ I finished my homework last night.

3. He is too young to go to school. (同义句)

    He isn't ______  ______ to go to school.

4. I have already finished the work. (用in 10 minutes 改写)

    I ______ ______ the work in 10 minutes.

5. He lit the birthday candles happily, _____  _____? (变反意疑问句)

人体触电的基本方式有单相触电和两相角触电两种方式。

简述营养素的概念。

胫神经受损后常出现跟行足。

典型的信息战武器有计算机病毒、“逻辑炸弹”、网络“黑客”等。请说出什么是计算机病毒，什么是“逻辑炸弹”。