提示：李明打电话给David，邀请塔下星期日去博物馆看展览。

（L=Li Ming；D=David）

L: Hello. This is Li Ming speaking, May I speak to David?

D:          51        . What's up, Li Ming?

L: What are you going to do next Sunday?

D: Nothing much. Do you have any ideas?

L:          52        ? There's a Russian oil painting exhibition there.

D: Good idea!        53       ?

L: Bus 202 will take you there.

D: Good.        54       ,then?

L: Let's meet just at the gate of the museum.

D:          55        ?

L: Half past nine.

D: All right. See you then.