We have brought in a good grain harvest for three years_________.

Women may have six months _______ after they give birth to a baby. 

If you really have to leave during class, you’d better leave____ the back door. 

China now aims to boost domestic demand, and this ______ would help the global economy.

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