comes will be welcomed to the open-air concert.A. WhateverB. WhoeverC. No matter whatD. N

问题补充：

comes will be welcomed to the open-air concert.

A. Whatever

B. Whoever

C. No matter what

D. No matter who

答案：

A. Whatever

(答案→)B. Whoever

C. No matter what

D. No matter who

解析：句意：无论谁来参加露天音乐会都会受到欢迎。可知主语是人。no matter who只能引导让步状语从句，不能位于句首，而Whoever则没有此类限制。故只能选B。