教一班活泼的孩子是项艰苦的工作。

It's hard work teaching a class of ___lively children.

他们对孙辈们抱有浓厚的兴趣。

They take a ___lively interest in their grandchildren.

会议上进行了一些热烈的讨论。

There was some ___lively discussion at the meeting.