There are many insects in the world thatnever do _______ harm to human beings

ve left the light on — Oh, so I have _____ and turn it off

We could have arrived earlier, but Tom insisted that I _______ too fast. [ ]

Many people are ________ as to what to do when thereis a fire

All of us must do_______ to help protect the environment，or we will have more hazy weather雾霾天气.