It’s quite natural that kids like to play with friends _______ their own age.

She strongly objected______my mother’s marriage. Surprisingly, my mother’s reaction _____it was rather calm .

  Four teams of three people would compete ______ the game and the winners would receive a free vacation.

Many large cities，such as Liverpool and New York，have had experiments of this kind，_______old factories turned into successful art centers.

_________ an old woman,the room was empty.