原文：He is much more at home on the subject than his elder brother

原文：He is much more at home on the subject than his elder brother.
译文：他比他哥哥花更多时间呆在家里研究这个题目。
改译：
【正确答案】：这个题目他比他哥哥懂得多。（考点：“is..at home on”的理解与翻译）