Don’t worry too much about________mistakes. They are ______ natural part of learning.

         A.不填；a        B. the；a          C. the；不填   D. the; the

 Don’t worry too much about       mistakes. They are _     natural part of learning.

       A.不填；a                B. the；a                  C. the；不填             D. the; the

Don’t worry too much about       mistakes. They are _     natural part of learning.

       A.不填；a      B. the；a C. the；不填  D. the; the

Don’t worry too much about ______ mistakes. They are _____ natural part of learning.

A. the, a　　　　　　　　 B. 不填, a　　　　　　 C. the, 不填　　　　　　　　 D. the, the