开采冲击地压煤层，应选择不留煤柱、（）、避免大面积悬顶的采煤方法。
参考答案：少掘巷道
24项版本HAMD临床症状严重的划界值是（）。
A.35分
B.24分
C.20分
D.17分
He knew the problem was serious and promised to look into it _____ he reached office.
A．at that moment
B．for that moment
C．immediately
D．soon
