Điền từ còn thiếu vào chỗ trống, hoàn thành câu

7. Water ______ at 100 degrees Celsius.
A. boiling
B. boils
C. is boiling
D. boil
8. Bettinaseldom______ television in the evening.
A.watches
B. watching
C. watch
D. has watched
9. Today she_________although her father drives her everyday.
A. is riding a bike
B. rides a bike
C. ride a bike
D. are riding a bike
10. Listen! Sam _______the piano.
A. are playing
B. am playing
C. plays
Dis playing
11. Look! Somebody________in the river.
A. is swiming
B. are swimming
C. am swiming
D. is swimming
12.____ his brother________a novel at the moment?
A.are/ writing
B. are written
C.writes
D. is/writing
13. John_____________that car now
A. am driving
B. is driving
C. are driving
D. drives
14. He__________motorbikes for 2 years
A. has been riding
B. has ridden
C. has been ridden
D. have been riding
15. My sister ________ for you since yesterday.
A. has been looked

B. has been looking

C. have been looking
D.looked