So, none of you in this room, I'm 100% confident, never ever got a smallpox vaccine.

所以我百分百确信这间教室里所有人,没有一个人接种过天花疫苗

耶鲁公开课 - 生物医学工程探索课程节选

So my walk is, it's not confident and I'm not sure if I'm strong in my step yet.

所以我的走姿不是特别自信，担心步伐会不稳。

I wonder if 实战 - SpeakingMax英语口语达人

But I'm not so confident anymore that it's the wrong thing to say.

但我不能再肯定那是错误的。

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First of all, I'm very pleased when this happens, because I'm pretty confident that I can do this under duress, but I may not do it right every time.

首先,我非常乐意你们指出我的错误,因为虽然我对这些公式了如指掌,但我并不能保证每次都写对

耶鲁公开课 - 基础物理课程节选