铺设无缝线路时必须将轨条置于滚筒上，并配合撞轨确保锁定轨温均匀，低温铺设时应用拉伸器张拉轨条。
参考答案：对
He didn’t succeed overnight. On the contrary, it was many years ______ his career took off.
A．since
B．that
C．before
D．after
.
饭后（服）（）
A．Co
B．H
C．p.c
D．s.o.s
E．St.
