It's human nature for parents to be fond of their children.

　　父母愛孩子是人類的天性。

　　It is human nature that all of us should be fond of beauty.

　　愛美是人的天性，每個(gè)人天生都追求美。

　　To be fond of art has been the human's tradition since the ancient time.

　　人類自古以來就有愛好藝術(shù)的傳統(tǒng)。

　　dict.cnki.net

　　Tom was saying you might be keen on yoga.

　　湯姆說你可能愛好瑜伽功。

　　They tend to be keen on volume of effort and overlook efficiency.

　　他們傾向于努力的量而忽略了效率。