Please write a letter to tell your friend ________ a better language learner.

1. A.
   how to become
2. B.
   when to become
3. C.
   to become how
4. D.
   why to become

Please write a letter to tell your friend ________ a better language learner.

[　　]

A. how to become

B. when to become

C. to become how

D. why to become

Please write a letter to tell your friend ________ a better language learner.

[　　]

A. how to become

B. when to become

C. to become how

D. why to become