People don't ask unmarried people Why are you single?.
人们不会问未婚的人“你为什么不结婚?”。
He's behind the rest of the class in reading.
他在阅读方面不如班上的其他同学。
Shops cater for the do-it-yourself craze not only by running special advisory services for novices, but by offering consumers bits and pieces which they can assemble at home.