_____ can we protect the environment in our daily lives— As for me, I think we are supposed to use both sides of paper and try not to use plastic bags.

The school has very strict rules about cheating in exams, so no one can ______ it.[ ]

There ___ a book on the desk .

It’s good for students to speak_______ English_________ .

She was so angry at he was doing ___she walked out without a word .