遇列车在区间发生故障，在确认救援列车（）分钟内不能挂走故障列车时，组织区间清客。
A.15
B.30
C.45
D.60
参考答案：B
sinx＞0，x∈[0，2π]的解集是______．
More than 20 people ________ in traffic accidents ________ last May.
A．have died, for
B．have died, since
C．have been dead, since
D．have been dead, for
