Humor (幽默感) is very important to human beings. We can never have too much of it.

Without humor, life would be ______. [ ]

A. disappointed

B. boring

C. bored

成语“朝秦暮楚”有多种解释，如比喻立场不坚定。假如用在商业上，该成语可以从侧面反映中国古代（）

①商人为获利而往来奔波

②商业交通比较发达

③长途贩运的商业现象

④秦楚两地商业最发达

A.①②③

B.①④

C.①③④

D.②③④