‘虚拟条件从句省略时if,倒装'怎样理解?

问题描述:

‘虚拟条件从句省略时if,倒装'怎样理解?
as引导的让步状语从句倒装,举几个例子解释

Hard as/ though he works, he makes little progress. (=Though he works hard, he makes little progress.)尽管他学习很努力,但几乎没取得什么进步.Child as/though he was, he knew what was the right thing to ...