Hurry up! The train _____ in two minutes.
—Will you give me a hand? I have some trouble_______ the scientific problem.—Don't worry. I'll try my best to help you _______.
You’d better_______ your cigarette when you are in the wood.
—What will the weather be like tomorrow?—It _______ be rainy, cloudy or sunny. Who knows?
—_______ are you leaving for Shanghai?—In a couple of months.
—This is _______ fascinating museum I have ever visited.—Yes. I’ve never seen a _______ one.