目前已经明确的与前列腺增生密切相关的因素有

A．吸烟

B．年龄

C．饮酒

D．雄激素

E．细菌感染

-Which tie is more suitable for me, the red one or blue one?

-I have no idea. You'd better take them __________.[ ]

A. all

B. each

C. every

D. both