6. The Red River________ very fast today-much faster than yesterday.

a. flows b. is flowing c. will flow d. is going to flow

7. While mother________ dinner the phone rang.

a. cooked b. had cooked c. has cooked d. was cooking

8. Fish________ on earth for ages and ages.

a. existed b. are existing c. exist d. have existed

9. The phone________ constantly since Jack won the first prize this morning.

a. has been ringing b. rang c. had rung d. had been ringing

10. The earth________ on the sun for its heat and light.

a. is depend b. depending c. has depend d. depends