他有自信走进一个满是陌生人的房间并开始交谈。

He has the ___confidence to walk into a room of strangers and start a conversation.

这门课程给了我处理工作中棘手情况的自信。

The course gave me the ___confidence to handle difficult situations at work.

他技术非常娴熟，但有时仍然缺乏自信。

He is very skilled, but sometimes he still lacks ___confidence.