Those are amazing objects in their own right, and also rather rare (perhaps because they're so difficult to spot) : there's eight known white dwarfs in the hundred nearest star systems to our sun.

白矮星是具个性的，也是非常稀有(可能因为定位它们很困难)令人惊异的恒星，在上百个离我们的太阳最近的星系中只有八颗已知的白矮星。

Indians already hold four of the top eight slots on the Forbes billionaire list, while Mexico's Carlos Slim has surpassed bill Gates to claim the No. 2 spot.

在《福布斯》亿万富翁榜上，印度人占据了前八位中的四个，墨西哥的卡洛斯·斯利姆(Carlos Slim)超过比尔·盖茨(Bill Gates)成为全球第二富豪。

While most of us should aim for that sweet spot of seven to eight hours of sleep a night, a small minority might need substantially less or substantially more.

我们大多数人最佳睡眠长度是每晚7至8小时，还有一少部分实质上可能会少于或多于7、8个小时。