光电器件输出电压达到最大值0.63倍时所对应的时间称为光电器件的响应时间它会影响调制频率上限。
参考答案:对
用方框中所给单词的适当形式填空,使句子通顺、正确。每词限用一次。
小题1:He’s unhappy because of his little dog’s__________ .
小题2:This factory was built in the _____________ century.
小题3:Welcome to Paris. It is one of the _____________ cities in Europe.
小题4:Would you mind_____________the door when you go out?
小题5:You’re only twelve years old.Don’t get your ears __________ .
登革热的传播途径是()
A.血液传播
B.粪-口传播
C.虫媒传播
D.空气飞沫传播
E.日常生活接触