. The main fact(or)s in human life are f
题型：选择题
问题：
. 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.
A．they play in what part
B．they play what part in
C．what part they play in
D．in what part they play