. The main fact(or)s in human life are five: birth, food, sleep, love and death. (One could increase the number— add breathing for instance— but these five are the most obvious.) Let us ask ourselves ________ our lives.
Don’t forget _____ the door when you leave.
The shop assistant sells the cap _____ fifteen yuan.[ ]
There is no doubt ______ you’ll be warmly welcomed by people there.
What did you do ________ April Fools’ Day?[ ]