倍数的表达法
once 表示一倍
twice 表示两倍
两倍以上用基数词加 times 表示
几种常见的表示倍数的句型
(1)…几倍（或分数）+ the size ( length，amount...) + of...
The earth is forty-nine times the size of the moon.
地球是月球的49倍。
(2)…倍数（或分数）+形容词（副词）比较级+ than...
His house is three times bigger than mine.
他的房子比我的房子大两倍。
The book is four times thicker than that one.
这本书比那本书厚3倍。
(3)…倍数（或分数）+ as+形容词+ as...
This factory is four times as big as that one.
这个工厂是那个工厂的4倍大。
Asia is four times as large as Europe.
亚洲的大小是欧洲的4倍。
(4)…times that of...，此句型多用于粮食产量、生产指标等方面的比较
In this area the grain output is five times that of before liberation，
这个地区的粮食产量是解放前的5倍。
(5)…倍数+ what引导的从句
He eats twice what I eat.
他的食量是我的两倍。