水泥杆线路一般使用（）做根部加固及保护。
A.卡盘
B.横木
C.底盘
D.垫木
参考答案：A, C
Although he knew little about the large amount of work done in the field , he succeeded ____other more well-informed experimenters failed.
A．as
B．unless
C．what
D．where
空分塔对墓础有什么要求？
