题目

△ABC的三边长为­­，，2，­△A'B'C'的两边为1和­，若△ABC∽△A'B'C'，则­△A'B'C'的笫三边长为_______  答案：解析:略   He _____ football regularly for many years when he was young.     A. was playing      B. played      C. has played                   D. had played