(届重庆市南开中学高三1月月考英语试卷)A ship in the harbor is safe,but that’s not __________ ships are built for.
—What do you think of my article, professor? —The former part is well written but _____ is just so so.
Young students are ______ not to smoke both in and out school.
He commanded that all the gates _____when it was getting dark in case thieves came in .
Mr. Black has been teaching English in a middle school _____ he came to China.
. — What's that noise? —Oh , I forgot to tell you. The new machine ________