I'm the fattest in my class.

在我的班级里，我最胖。

That's (the fattest) cat in my house.

那是我家最肥的一只猫。

Fattest and first, could anything be worse?

最胖的先来，还有比这更糟是事情吗？

The fattest person , s name is unknown.

最胖的人的名字，还未得知。

Now Britain is the fattest country in Europe.

英国成欧洲“最胖”国家。