大面积冒顶时煤壁的预兆有（）。
A.片帮增多
B.煤质变软
C.电钻打眼省力
D.煤层层理紊乱
参考答案：A, B, C
—Is that the small town you often refer to?
—Right, just the one ________ you know I used to work for years.
A．that
B．which
C．where
D．what
生长发育在12岁左右达到顶峰的组织器官是（）
A.上颌骨
B.下颌骨
C.颅底骨
D.淋巴
E.睾丸
