--- Is it convenient to you if I call you up at 9 o’clock tomorrow morning?

--- I’m afraid not. I _________ a speech then.

A．was giving

B．will be giving

C．am giving

D．will have given

低钾血症是（）。

A.床上常表现、肢体抽蓄

B.严重时可发生室性心动过速，甚至室颤

C.心电图表现为T波高尖、呈帐蓬样

D.常伴有代谢性酸中毒

E.机体总钾量总是减少的