Question

(       )8.  Jack always tries_________  best ____________ everything well.

   A. his; do              B.  her; doing
   C.  his; to do          D.  her; to do

Answer 1

8.      C   try one's best to do sth.意为"尽某人最大努力做某事"，其中的one's要根据句子主语来确定其形式。