Mr.Smith has been here for many years, he has few friends.
The Greens used to live in London and now they________in Beijing.
—What’s the matter________your computer?—It doesn’t work.
The problem is________difficult that nobody can work it out.
—Smoking is bad for your health.—You’re right.I decide to________.
—How did he use to go to school?—By bike.But now he’s used to________to school.