另一题关于刘振民的：（（

The mistakes children make i learnin gto speak tell linguists more about how they learn language than the correct forms they use.

a) how they learn language than

b)how one learns language than

c)how children learn language than do

d)learning language than

e)their language learning than do

KEY: c

问题：它的比较成份中是怎样平行或对称的给出的解释看不明白。

谢谢了