flaw|flawed|flaws

你的推理中有一个缺陷。

There's a ___flaw in your reasoning.

这个理论虽然有趣，但存在严重缺陷。

The theory, while interesting, is deeply ___flawed.

然而，设计中有一些小缺陷。

However, there were some minor ___flaws in the design.