倍数表达法：
 A + 谓语+倍数+the +n.(size/ height/ length……)+of B
 A + 谓语+倍数+as + abj.+ as B
 A + 谓语+倍数+adj.比较级+than B A + 谓语+adj.比较级+than B+by+倍数
1).This square is twice the size of that one.
 This square is twice as large as that one.
 This square is once larger than that one.
2).This factory produced three times as many cars as they did 10 years ago.
3).He is 3 years older than I- He is older than I by 3 years