1. They demand sacrifice and unselfishness, a long-term investment of the parents' time and money.
    他们需要我们做出自我牺牲和无私奉献，也就是父母对子女在金钱和时间上的长期投入。

2. Father instilled unselfishness in his son.
    父亲逐渐给孩子灌输无私的思想。

3. Father instilled unselfishness in his son.
    父亲逐渐给孩子灌输无私的思想。