It’s good for you to keep_______when you have something difficult______．

A．trying，to do                                 B．doing，to do it   

C．to try，to do                                 D．trying，to be done

It’s good ________ you to keep ________ when you have something difficult ________．

1. A.
   for; trying; to do
2. B.
   of; trying; doing
3. C.
   for; to try; to do
4. D.
   of; trying; to be done

 It’s good ___ you to keep____ when you have something difficult_____.

  A. for; trying; to do                 B. of; trying; doing  

  C. for; to try; to do                 D. of; trying; to be done