英语：请问这句话对吗?有没有更好的说法呢?They think those activities waste their time.
网友回答
不好.要么是：
They think those activities are going to waste their time.
或者：They think those activities have wasted their time.
或者：They think those activities are a waste of time.
或者：They think those activities were a waste of time.
======以下答案可供参考======
供参考答案1:
They think it's wasting time to doing those activities.
供参考答案2:
.