С) you (feel) cold unless you wear a coat . i*ll arrive at 10 a.m. if there (not be ) heary traffic . unless he (stop) smoking he*ll be seriously ill. the teacher will be if you (not do ) homework.

You will feel cold unless you wear a coat.
I'll arrive at 10 a.m. if there isn't heavy traffic.
Unless he stops smoking he'll seriously ill.
The teacher will be if you don't do homework.