— What’s the main purpose of tonight’s meeting?

— We are going to talk about the problem _______ at the last meeting.

A．having discussed

B．to be discussed

C．being discussed

D．discussed

田田要爷爷出一道趣味题，爷爷给他念了一个顺口溜：湖边春色分外娇，一株李树一棵桃，平湖周围三千米，三米一株都栽到，漫步湖畔美景色，可知桃李各多少( )

A．499棵，500棵
B．499棵，499棵
C．500棵，500棵
D．500棵，499棵