—I am afraid I am a man without luck. I have been trying and have always been turned away.

—________. Just have a little patience.[ ]

A. Things at the worst will mend

B. Time and tide wait for no man

C. Fear always springs from ignorance

D. Troubles never come singly

西方经济学中的国际直接投资理论主要有( )。

A．垄断优势理论

B．产品生命周期理论

C．国际生产折衷论

D．内部化理论

E．比较优势理论