他花了3小时做家庭作业（用英语翻译）
问题描述：
他花了3小时做家庭作业（用英语翻译）
答
It took three hours to do homework for him.
或者是
He spent three hours to do homework.
答
He spent three hours doing his homework.
答
He spent 3 hours doing his homework.或者It takes him 3hours to finish his homework.