They will never succeed,__hard they try.A because B however C when D since不要光说答案

问题描述:

They will never succeed,__hard they try.A because B however C when D since
不要光说答案

B
无论他们多么努力地尝试,他们都将无法成功.
however无论多么.
whatever无论什么
whenever无论什么时候