（）和输电线路，必须经常检查和维护。
A、水泵
B、水管
C、闸阀
D、排水用的配电设备
参考答案：A, B, C, D
The general at last got a chance to visit the village _______ he used to fight, _____ he had been dreaming of for years.
A．that/which
B．where/that
C．in which/what
D．where/which
两汉时江南地区落后于黄河流域的原因有：①地势复杂 ②气候过于炎热潮湿 ③人口稠密 ④生产技术落后
A①②③ B①②④
C②③④ D①②③④
