在下面对话的空白处填入适当的单词，使对话的意思完整、通顺，每空限填一词（含缩写词）。

W: Did you go to the 【小题1】 yesterday?

M: Yes, I did.

W: I went with my friends Jim and Frank.

W: What animals did you see there?

M: We  【小题2】  tigers, lions, elephants and koalas.

W: Do you know koalas from?

M: Yes, they are from Australia.

W: What else did you do there?

M: We took some 【小题3】 with Jim’s camera. And we enjoyed an animal show.

W:  【小题4】  was the show?

M: I think it’s boring. I can’t 【小题5】 it.

W: Did you stay there for long?

M: No. We were there for about an hour. Then we went home.

通常把封住畦口、停止向畦田放水时，畦内水流长度与畦长的比值叫（）

A.灌水延续时间

B.灌水定额

C.入畦流量

D.改水成数