Our city has developed into a big city, which is ________ it used to be．
A.four times larger than thatB.four times the size ofC.four times the size larger than thatD.as four times the size as that在线课程A
句意为：“我们市已发展为一个比过去大四倍的城市。”B项后面没有比较对象that，因此错误。