Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

The effect of this drug has been proven to be extremely harmful a long time ago.

D. where

D. stands for

A. Tom told Mary that he will tell her about that tomorrow.

B. Tom told Mary that she would tell him about that the day before.

C. Tom told Mary that I would tell you about that the next day.

D. Tom told Mary that he would tell her about that the next day.

A. Zoos: The Best Opportunity to Learn About Animals

B. Methods of Learning About Animals at School

C. Research on Learning About Animals

D. Learning About Animals at School

D. contained

B. most dangerous

D. the more dangerous

A. If only Joe were here with us to help fix this technical issue.

B. Provided that Joe is here with us, he won't know how to fix this technical issue.

C. Joe will know how to fix this technical issue even if he is not here with us.

D. We wish Joe had been here with us and fix this technical issue.