采区巷道服务年限一般多长？
参考答案：
采区巷道随掘随采，服务期限短，一般短的只有1-2个月，长的有0.5-1年。
—Do you really think what he said was practical?
—I don't entirely agree, but ________.
A．I don't care
B．just let it go
C．go ahead
D．I doubt it
