包络检波器中用来取出调制信号的滤波器是高通滤波器。

If he __________ my advice, he wouldn't have lost his job.

A．followed

B．should follow

C．had followed

D．would follow

—I have bought a new watch . 

—When and where _______ you _______ it? [ ]

A. do; buy

B. did; buy

C. have; bought

D. will; buy

核纤层

氯唑西林属于（）。

A.耐酸青霉素类

B.耐青霉素酶类

C.广谱青霉素类

D.抗铜绿假单胞菌类

E.抗革兰阴性杆菌类

就下列有关历史文献所反映出的信息，其中错误的是（）

A.文献①的核心思想即洋务派的宗旨

B.文献②的核心思想是无处不均匀，无人不饱暖

C.文献③的核心思想是宣传维新变法

D.文献②在社会经济方面的主张和社会发展趋势相矛盾