题目内容：

说明理由
1.The length of the reading passage increased progressively,from about 300 words in the early units to nearly ______ in later ones.
A.three times the length of B.three times of the length
C.the length three times of D.three times this length

优质解答

倍数的表达法
不管用那种形式,“倍数”首先应该放在结构外面,所以C错
答案应该是A
倍数+the +名词+of
其它表达方式：
倍数+as+adj/adv.原级+as
倍数+ adj/adv.比较级+than