为什么要花钱保护国内不知感恩一毛不拔的吝啬鬼呢？

Why spend money protecting ungrateful, stay-at-home skinflints?

youdao

科学家们认为，不知感恩的人实际上是自欺欺人。

Ungrateful people are actually cheating themselves, scientists believe.

youdao

我没有让你学这最后一个爬树的技巧，因为我怀疑你可能会是个不知感恩的朋友。

I kept the last technique of the tree climbing from you just because I suspected you might be can ungrateful friend.

youdao