你能分辨出哪个苹果更甜吗？

Can you ___tell which apple is sweeter?

这项调查告诉我们关于青少年生活的什么信息？

What does the survey ___tell us about the lives of teenagers?

我们都看过那些告诉我们汽车污染问题的报告。

We have all seen the reports which ___tell us about the problems of pollution from cars.