今天我们来学习如何表达英语学习中的倍数关系，
首先我们看他们的表达结构，然后举个例句。
a. 主语+谓语+倍数（或分数）+ as + adj. + as
I have three times as many apples as you.
我的苹果有你三倍那么多。
b. 主语+谓语+倍数（分数）+ the size (amount，length…) of…
The earth is 49 times the size of the moon.
地球的体积是月球的49倍。
c. 主语+谓语+倍数（分数）+ 形容词（副词）比较级+ than…
The corn output is 19 percent higher this year than that of last year.
今年玉米产量比去年高19%。
d. 还可以用by+倍数，表示增加多少倍.
The production of grain has been increased by four times this year.
今年粮食产量增加了四倍。
ok, 以上就是今天的所学内容。
