Protecting the earth is not ____ to be left to the government．Everybody should be concerned．

Learning experiences happen to us throughout our lives, and not too long ago, I had _______ that I would like to share.

How wonderful it will be that whoever is in need of a job can get        ．

I don’t like _______my younger brother follows me around.

We are tired of doing ________ homework every day; most of _______ is of no use but of  
mechanical drill.

The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.

_______is certain ______ the Normans conquered England in 1066 and then English changed.

I have bought two books recently, but ________ interests my father.

Why don’t you bring ______ to his attention that you are too ill to go on working?

All the ladies wear beautiful clothes for the celebration. Some are dressed in red, _______ in purple.