―Look at the dark clouds. It _____ rain soon.―I’m afraid so, and we _______ stay at home now.

The villagers used to______ drinking water from theriver nearby, but now they spend two hours _______ to get it in the mountainbecause of the dry weather in Yunnan.

Lots of the scientists in our country are working hard to ____the planet Mars .

ite a number of children, theirteachers’ advice is more acceptable than ____ of their parents

We built this factory ______ top speed andminimum(最少的) cost.