桥梁支座是连接桥梁上部结构和（）的重要结构部件。
A、下部结构
B、墩台
C、桥台
D、底板
参考答案：A
—Could you let me know _______ yesterday?
—Because the traffic was heavy.[ ]
A. why you come late
B. why you came late
C. why did you come late
D. why do come late
使用模块式SPD时，接地线的长度应小于（）。
A.3m
B.2.5m
C.2m
D.1.5m
