题目

一个三位数，个位，百位上的数字的和等于十位上的数字，百位上的数字的7倍比个位，十位上的数字的和大2，个位，十位，百位上的数字的和是14，求这个三位数。 答案： 275；The noise of desks ______ could be heard out in the street.A.opening and closingB.opened and closedC.to be opened and closedD.being opened and closed