1.A+谓语+倍数+as+形容词/副词原级+as+B
Our classroom is three times as big as their classroom
我们班的教室是他们班的三倍
2.A+谓语+倍数+形容词/副词比较级+than+B
Our classroom is two times bigger than their classroom
我们班的教室比他们班的大两倍（比他大两倍就是是他的三倍的意思）
3.A+谓语+倍数+the+名词+of+B
Our classroom is three times the bigness of their classroom
我们班的教室是他们班的三倍