Milk will turn sour soon on hot days ______ it is stored in the refrigerator.
The reason ___ he is absent is ___he has a bad cold.
_______ people died ______ starvation that year will never happen.
________ hard it might be, I will work it out.
You may give this message to _________ is at office.
You may have one of these; in other words, you have ______ you choose.