You are one tough customer, you know that?

你是一个难搞的客人，你知道吗？

They were all super-happy to try the toothpaste tablets, but they were tough customers.

他们都非常乐意尝试牙膏片，但他们都是挑剔的顾客。

Ooh. Look at you, C-137. You, aren't you a tough customer.

看看你自己 C-137 你真是個難對付的客戶。

From our limited time with her, she strikes me as a pretty tough customer.

在我们跟她的短暂相处中，她给我的印象是个坚强的人。