We have done a lot to make our city cleaner, but it’s still not enough.– So we should do ________ to improve it.

I don’t think fast food is good for our health, so I_______ go to MacDonald.

Helping the people in the earthquake in Nepal has become an unforgettable in her life.-I think it will influence her a lot.

I don’t know _______to do next? –It’s easy .Press the red button in 2 minutes.

He has made another wonderful discovery, _____ I think is of great importance to science.