下列产业属于资源密集型产业的有（）。
A.采煤工业
B.采油工业
C.汽车工业
D.服装加工业
参考答案：A, B
Crossing roads without taking traffic lights into consideration, _____ they are part of a crowd, has been labeled as the “Chinese style of crossing roads”.
A．since
B．as if
C．though
D．so long as
高压电流互感器（）接地。
A.必须
B.宜
C.不允许
D.可以
