The old scientist took up walking as a regular form of exercise, which, of course, is of great to his heath.
—Hurry up! Father is waiting for us downstairs. —OK,Mum.I________changed and it won't take long.
________a lot of other countries,we're in an economic recession(衰退).
He was ___in the car accident.
It is the fourth time that Jenny ____ you in a week.
I don’t know _____,