It is not only closely linked to an individual's interests but also matters to the whole society.

它不仅与个人利益密切相关，同时也和整个社会利益息息相关。

It takes more than a brief encounter on a bus to distinguish between courteous convention and individual interest.

公共汽车上一次偶然的邂逅不能区分出何谓公众礼仪何谓私人兴趣。

After all, it would be in each of their individual interests to make a better product to outsell the others?

毕竟，制造出更好的产品来超越其他产品才符合他们各自的利益吧？

It ultimately depends on the individual interests and needs of the child, as well as the specific circumstances of the family.

这最终取决于孩子的个人兴趣和需求，以及家庭的具体情况。