Definition: used to introduce the first idea, reason, etc. in a series Level: A2
首先，我想问你几个关于你童年时期的问题。
___First ___of ___all, I'd like to ask you a few questions about your childhood.
首先，谢谢你的来信。
___First ___of ___all, thanks for your letter.
首先，让我自我介绍一下。
___First ___of ___all, let me introduce myself.
