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