1.What in the world did they think they were doing?他们到底认为自己在做什么？

2.I think we should go back to first principles.我认为我们应该回到基本原则上。

3.I always think of you as one of the family.我一直把你当成自家人。

4.I think you should go back to your original plan.我认为你应该回头执行你原来的计划。