In spring, we can often hear some birds_______ in our school.

It’s time for the weather report. Could I ______ the TV, Dad?

What is _________ way of going to school in your country?

I can’t find my ticket. I think I must have lost_____.

hat do you think of genetically modified food (转基因食品)? —We all think ______ is careless ______ some scientists to say it is safe before doing any experiment.