我原以为会议是上午10点开始，而不是9点。

I ___was ___under ___the ___impression that the meeting started at 10 AM, not 9.

许多人错误地认为学习一门语言很容易。

Many people are ___under ___the ___mistaken ___impression that learning a language is easy.

从你的邮件来看，我认为你需要更多关于这个项目的细节。

From your email, I ___am ___under ___the ___impression that you need more details about the project.