Directions: In this section,there are
10 incomplete sentence& You are required to complete each one by deciding on
the most appropriate word or words from the 4 choices marked. Then you should
mark the corresponding letter on the Answer Sheet with a single line through the
center. Not until I began to work ______ how much time I had wasted.
A. have I realized
B. did I realize
C. I have realized
D. I realized