Can you see______11-year-old boy and ______one-year-old cow in the field?
My friend and I joined a program ______ Green China.
Bad luck! My watch is broken, ____ it doesn’t _____.
—Beijing has improve a lot these years. —_____ and_____.
_____ we have built “the Green Wall’, _____we still need to work hard to protect our environment.
— Tony, may I have a talk with you now? — Sure. Oh, it’s noisy here. Let’s go ______.