晶体三极管由两个背靠背的PN结组成,从结构上分为()和NPN型两种。
参考答案:PNP型
用所给单词的正确形式填空。
1. Will you please ____________ (go) to the zoo with me?
2. I am ____________ (thin) than Kate.
3. My ruler is as ____________ (long) as yours.
4. I like ____________ (jog) every morning in the park.
5. The ____________ (butterfly) fly higher than the bees.
6. ____________ (do) Helen ____________ (go) to school earlier than you?
7. Who would like ____________ (read) the new words for us?
8. Please get off the bus at ____________ (three) stop.
安全生产管理工作应该做到预防为主,通过有效的管理和技术手段,减少和防止人的不安全行为和物的不安全状态,这就是()。
A.强制原理
B.预防原理
C.人本原理
D.动力相关性原理