Correct or improve the translation of the following English sentences. 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：

Correct or improve the translation of the following English sentences. 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：

这个题目他比他哥哥懂得多。