This apple is _____ than that one.
Mike likes playing ____ golf while I like playing _____ piano .
Not only oral English but also written English _____ important.
—We’ll make a trip to Hainan Island next weekend. Will you go with us? —No, I can’t _____ it at present because I have little money.
—How many students are there in the classroom? —_____. I don’t know where they have gone.
The rubbish _____ is produced every day is becoming a serious problem in cities around the world.