目前，沙林是国外军队装备的主要神经性毒剂之一。

根据对话内容，从对话下边方框内的选项中选出能填入空白处的最佳选项，并将代表该选项的字母填入横线上。选项中有两项为多余选项。
A: What’s the date today
B: It’s June 16.
A: (16) Then it’s Dragon Boat Festival today, isn’t it
B: Yes. (17)
A: Did you have rice dumplings this morning
B: Sure. (18)
A: I didn’t.
B: What a pity! But I happen to have got some with me. (19)
A: I’d love to. By the way, why do you call it Dragon Boat, Festival
B: Because in China, people race dragon boats this day every year.
A: Oh, I see. (20)
B: Yon are welcome.
A．We Chinese usually eat rice dumplings this day.
B．I hate eating rice dumplings.
C．Thank you for your rice dumpling.
D．I don’t think so.
E．Would you like to have one
F．Already
G．How about you