the rate is prevalent, wrong, but why?

Dear guys,

I am listening to ShiLin's SC tutorial

He keeps mentioning that we cannot say 'the rate of wage is prevalent'

and the rate itself is a number.

but why?

thanks for your help(in advance)

有没有题目啊?

没有题目，是石林的讲座中的，在讲逻辑搭配中说，rate是数字

不可以用prevalent描述

看来只好硬背了

贴几个rate的题目，供大家讨论：

大全－68

68.   After the Colonial period’s 50 percent mortality rate, life expectancy improved for children, but as late as the nineteenth century about one child in three died before reaching the age of six.

(A) After the Colonial period’s 50 percent mortality rate, life expectancy improved for children, but

(B) Even though children’s life expectancy, which improved over the Colonial period’s 50 percent mortality rate,

(C) Although life expectancy for children improved after the Colonial period, during which the mortality rate was 50 percent,

(D) While there was an improvement in life expectancy for children after the 50 percent mortality rate of the Colonial period, still（C）

(E) Despite children’s life expectancy improvement from the Colonial period’s 50 percent mortality rate,

大全－122

As a result of the continuing decline in the birth rate, less people will enter the labor force in the 1980’s than did in the 1960’s and 1970’s, a twenty year period during which people born after the war swelled the ranks of workers.

(A) less people will enter the labor force in the 1980’s than

(B) less people will be entering the labor force in the 1980’s as

(C) fewer people will enter the labor force in the 1980’s as

(D) fewer people will be entering the labor force in the 1980’s as（E）

(E) fewer people will enter the labor force in the 1980’s than

大全－140

   As the housing affordability gap widens, middle-income families are especially hard-hit, and these families can no longer qualify to buy homes, and rising rental rates force them to use far more than the standard 25 percent of their incomes for housing, leaving them with no equity or tax write-offs to offset the expenditures.

(A) and these families can no longer qualify to buy homes, and

(B) since these families can no longer afford to buy homes, furthermore

(C) for these families can no longer afford to buy homes, yet

(D) and these families can no longer afford to buy homes; however,（C）

(E) and these families can no longer afford to buy homes, for

大全－146  Astronomers studying the newly discovered star say that it provides clues about our galaxy’s origin, that it may supply data about how fast our galaxy is expanding, and moreover it is perhaps the most distant star in the entire Milky Way.

(A) about how fast our galaxy is expanding, and moreover it is perhaps

(B) regarding the speed our galaxy expands at; moreover, they think it may be

(C) about how fast our galaxy expands and perhaps be

(D) on the galaxy’s expansion rate and perhaps（E）

(E) about how fast our galaxy is expanding, and that it is perhaps

好像没有修饰上的问题。大全－146也是用adj形容rate。

prevalent。。。找不到相关的例子来证明。

rate要么是具体数字， 要么是高， 低。 没有广泛这样的修饰。

好比钱只有多少， 没有好钱， 坏钱。