----Why are your hands so dirty?
----I ____________in the garden.
A. was working B. have worked C. worked D. have been working
If I can help ____, I don’t like working late into the night.
A. so B. that C. it D. them
---Why not open the windows to let _____cool air in?
---I’d rather you didn’t. ________air in out town is terribly polluted.
A. a; The B. /; The C. / ;/ D. the; /
----Are my clothes too casual?
----No. You can go ____you are.
A. as B. what C. that D. where
How ___ I help them to understand when they won’t listen to me?
A．can B．would C．may D．must
In summer, food will go bad if________in room temperature.
A．leaving B．left C．being left D．having left
