1. I don't tell her that he's not my baby because I'm tired of explaining.
    我没告诉她他不是我的孩子，因为我懒得解释了。

2. I began watching Sam as a favor to Ann when I was in graduate school.
    还在研究生院读书时，我就开始帮安照看山姆。

3. It turns out that a scientist can see the future by watching four-year-olds interact with a piece of candy.
    人们发现，通过观察一个四岁孩子怎样处理一块糖，科学家可以预测其未来。