开关整流器的基本电路中,()的作用是将交流输入电压整流滤波变为平滑的高压直流电压。
A、输入回路
B、开关控制器
C、高频变压器
D、功率变换器
参考答案:A
单词拼写
1. The Taiwan S____ separates Taiwan Island from the mainland.
2. Now in China, an increasing P___ of the population have their own cars.
3. As the wage was low, few people a ____ for the position.
4. That accident o ____ at midnight.
5. My lather h ______ three men to help him with the harvest lastsummer.
6. Only a few of them thought highly of the plan. The m didn't agree to it.
7. He is an o ____ looking man.
8. ____( 显然) ,he has lost interest in physics.
9. The government announced additional rules on _____ ( 移民 ).
10. It is_____( 相信)that before long there will be more trees
对于重置成本变动较大的公司、固定资产较少的服务行业,不适合用()来对证券进行估值。
A.市盈率
B.市净率
C.股价/销售额比率
D.市值回报增长比