架空输电线路一般由（）等构成。
A、导线、绝缘子、金具；
B、杆塔及基础；
C、避雷线；
D、接地装置。
参考答案：A, B, C, D
保安单元动作后将产生那些现象（）.
A、电话不通
B、电话占线
C、测量室告警模块告警
D、保安单元上的灯亮
听句子，缩写原文。（）
A．Many university students prefer soft drinks to fresh fruits.
B．Most of them are first-or-second year college students.
C．A number of college students refuse to disclose their identities.
D．Not many students are interested in our research projects.
