倍数表达法有三种：
倍数＋原级 倍数＋比较级 倍数＋名词短语
例如:和---三倍一样长
1.three times as long as
2.three times longer than
3.three times the length of
再如：和---四倍一样宽
1.four times as wide as
2.three times wider than
3.three times the width of