GWD-24-Q 21:

Nobody knows exactly how many languages there are in the world,

partly because of the difficulty of distinguishing between a language

and the sub-languages or dialects within it, but those who have tried

 to count typically have found about five thousand.

A.     and the sub-languages or dialects within it, but those who have

tried to count typically have found

B.     and the sub-languages or dialects within them, with those who

have tried counting typically finding

C.     and the sub-languages or dialects within it, but those who have

tried counting it typically find

D.     or the sub-languages or dialects within them, but those who tried

to count them typically found

E.      or the sub-languages or dialects within them, with those who have

tried to count typically finding

答案A 但是 A中it 指代什么 对

partly because of the difficulty of distinguishing between a language

and the sub-languages or dialects within it不清楚

partly because of the difficulty of distinguishing between a language

and the sub-languages or dialects within it不清楚

partly because of the difficulty of distinguishing between a language

and the sub-languages or dialects within it不清楚

it指代a languege

partly because of the difficulty of distinguishing between a language

and the sub-languages or dialects within it意思是：部分是因为很难把一种语言和他的分支、或者

和他内含的方言区分开。

同意二楼的分析