81. With the aid of public bids(公开招标) our town government decided to _____ the two villages by a highway.

We must do everything we can _________ our earthclearer and safer.

One evening when it was so warm, I stayed awake _________ until half past eleven in order to have a good look at the moon by myself.

The squirrel was lucky that it just missed ________.[ ]

Does the newly published detective book sell well? —No．it will only a limited public．