什么特种作业?
参考答案:
在劳动过程中容易发生伤亡事故,对操作者本人,他人和周围的设施存在重大危险因素的作业。从事此类工作的人员称特种作业人员。
四名男生三名女生排成一排照相,则三名女生有且仅有两名相邻的排法数有 ( )
A.3600
B.3200
C.3080
D.2880
Having checked the doors were closed, and ___ all the lights were off, the boy opened the door to his bedroom.
A.why
B.that
C.when
D.ours