埋设在人行道下的0.4管道，其埋深可以为（）
A.0.3
B.0.4
C.0.5
D.0.6
参考答案：D
What impresses me most is ____ heappears in front of others, he wears a smcere and charming smile. [ ]
A. what
B. which
C. that where
D. that whenever
后张法预应力钢筋张拉后，需进行孔道灌浆，其目的是( )。
A．释放多余应力B．保护预应力钢筋C．弥补应力损失D．防止混凝土弹性压缩
