hard one may work, one cannot master a foreign language in a year or two.
A. Though
B. As
C. While
D. However
网友回答
A. Though
B. As
C. While
(答案→)D. However
解析:考查让步状语从句:句意:无论一个人学习的多么努力,一两年都不可能掌握一门外语。However 引导让步状语从句的结构是:However+adj/adv+主谓,A. Though虽然,可以引导让步状语从句,但是不能用倒装,B. As引导让步状语从句的时候,应该用倒装,hard应该提前,C. While虽然,可以引导让步状语从句,但是不能用倒装,选D.