The Blacks ______ dinner when I knocked at the door.
A. is having B. are having C. were having
I don’t think she ______ her homework in 2 hours.
A. finishes B. finishing C. will finish
I believe that there will be _____ pollution and _____ trees.
A. fewer; more B. less; more C. fewer; fewer
--- Would you please tell me_____ the timetable (时间) has changed?
--- Because the students should have a rest at noon.
A. if B. when C. why
If it_____ sunny tomorrow. I___ fishing.
A. is; go B. will be; go C. is; will go