金实不鸣的原因为（）
A.风寒犯肺
B.虚火灼肺
C.肺气不足
D.肺肾阴虚
E.燥邪犯肺
参考答案：A
—It's a long time________I saw you last.
—Yes,and what a pity it is now that it will be a long time________we see each other again.[ ]
A. before; since
B. since; when
C. since; before
D. when; before
电网调度管理的任务及要求？
