This saying is completely unfounded 这种说法完全是无稽之谈
I have to say this fear is unfounded.
我必须说,这种担心纯属杞人忧天。
We hold that their proposal is unfounded.
我们认为他们的建议是无事实根据的。
The blame you laid on China over the issue of the Sudan is unfounded.
你在苏丹问题上对中国的指责是不符合实际的。
应用推荐