Don't be selfish 不能太自私
A mother is admonishing her son. 母亲正在劝戒她儿子
Now, John, don't be selfish. Let your little brother share the bicycle with you.
JOHN,不能太自私,把你的自行车跟你的弟弟一起分享
But Mother, I do. I ride it down the hill, and he rides it up the hill.
妈妈,我有啊,我骑下山,他骑上山嘛