Q1

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 about five thousand.

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

DE的 or 很明显可以排除;

AC的 it 按照句意应该指代"languages", 所以 it 应该錯了吧 

so 正确答案是B吗, 但是B那个 with 怎么看怎么怪,

大家选什么啊  ?