Exercise 8: Choose the underlined part in each sentence that needs correcting 

1.(A)Playing tennis (B)is not as easy (C)than (D)playing badminton.
2.I have (A)known my (B)best friend (C)since we (D)are at elementary school.

3.Christopher Columbus (A)has discovered America (B)more (C)than 500 (D)years ago.

4.Your story is the same (A)of (B)the one i (C)read (D)last week.

5.How (A)is a (B)salesman different (C)with a (D)businessman?