根据对话内容，从对话后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

— Good morning. 1______. 

— Yes. I'd like some information about English courses in your college. 2______ 

— Yes, there's a beginners' course on Monday evenings at 7:30.

— On Monday? 3______

— Yes, I'm afraid so.

— Well. 4______ But do you think you'll have a course on some other night in the future? 

— Well. 5______ Perhaps we will offer one in the future.

A. I work on Mondays, so I'm afraid that's no good for me.

B. Do you have any courses for complete beginners?

C. Is that the only course you've got?

D. Why not come earlier?

E. Can I help you?

F. I want to have English lessons.

G. Wait for some time, please.

葡萄糖通过一般细胞膜

A．通道中介的易化扩散
B．继发性主动转运
C．单纯扩散
D．原发性主动转运
E．载体中介的易化扩散