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.

Let’s go hiking _____staying at home, shall we? —A good idea.[ ]

Della likes dancing, but doesn’t like swimming.. —-_____.

I don’ t want to talk to Sarah now. She is mad ________ me these days. [ ]

The boys put ___________ school bags on the playground.