Tom is only two years old, ________ he shouldn't be left alone.
A.and B.so C.but D.for
________ he has said sorry to you, please give him another chance.
A.When B.Since C.Before D.Until
Jane, please turn off the lights ________ you leave the classroom.
A.after B.before C.until D.unless
I am quite busy. I don't know ________ I'm free or not tonight.
A.if B.unless C.whether D.when
Put on your coat, you will catch a cold.
A.and B.but
C.or D.so
Tommy, don't make a noise! ________ you have any questions, please put up your hands.
A.Before B.If C.Though D.Until
