单项选择题
A．advantages of working at home in the U. S.A. B．computers widely used in the U. S.A. C．the necessity of working at home in the U. S.A. D．working at home in the U.S.
A．are seldom punished for doing wrong B．can find something new and interesting all the time C．always want to be young D．live a perfectly happy life if they always behave well
A．visited B．broke into C．entered D．saw