答案:though引导让步状语从句倒装用法如下:
1. 副词/形容词/名词短语 + as/though + 主语 + 动词
Eg: Hard as he tried, he failed the exam.
2. 动词原形 + though/although + 主语 + 助动词/情态动词
Eg: Try though he did, he couldn't solve the problem.
3. 部分倒装:否定词/only + 状语 + though/although
Eg: Only when he finished the task did he go home.