在大信号包络检波器中，由于检波电容放电时间过长而引起的失真是（）.
A、频率失真
B、惰性失真
C、负峰切割失真
D、截止失真
参考答案：B
社区动员的根本目的描述最恰当的是（）
A.提高健康水平
B.提高知晓率
C.提高群众参与性
D.找出社区主要卫生问题
E.确定社区卫生资源
Choose the right description of the part of sentence underlined.
(选出对句子画线部分结构描述正确的选项.)
1.It is sometimes hard to understand each other.?
A.主语 B.谓语 C.宾语 D.表语
2.I think this is a good way of improving your English.?
3.I just can't think of anything to say. ?
A.主语 B.宾语 C.定语 D.表语
4.Listen to BBC programmes to improve our listening.?
A.主语 B.状语 C.宾语 D.表语
5.I want to know where the newspaper is.?
A.主语 B.定语 C.宾语 D.表语
6.At a bus stop he sees three people waiting for a bus.?
A.主语 B.定语 C.宾语 D.补语
of anything to say. ?