My father gave me an expensive car. I think we should by some canned food before a typhoon

1) My father gave me an expensive car.
=> The car which_____________________
2) I think we should by some canned food before a typhoon.
=> I suggest that some___________________________
3) I don't know how to use this machine, so I can't help you.
=> If___________________________________
4) He was allowed to go out but he wanted to stay home.
=> Although___________________________________
5) Hurry up or you will be late fo school.
=> Unless
6) My advice to you is this: try to relax before the exam.
=> If_____________________________________
7) This is Mrs. Hoa. Her son won the scholarship last semester.
=> This is Mrs. Hoa ________________________________
8) In spite of the heavy rain, we went to school.
=> Although______________________________________
9) How about collecting these waste things for recycling?
=> I suggest that these waste things_______________________
10) A generous man gave the charity considerable money.
=> The man______________________________
11) A lot of people pour into streets during the rush hour, so there are often traffic jams.
=> Since______________________________
12) The last time she worn that dress was on her sister's wedding.
=> That dress hasn't___________________________________