“维规”规定：无线通信维修工作包括（）。
A.日常检修
B.定期轮修
C.重点整修
D.局部整治
参考答案：A, B, C
Over the past decades,sea ice___________in the Arctic as a result of global warming. [ ]
A. had decreased
B. decreased
C. has been decreasing
D. is decreasing
货物运输的基本条件是什么？
