firstly
adv. （用于引出一系列陈述）首先，第一
例句
There are two reasons for this decision: firstly...
做此决定理由有二：第一…
《牛津词典》
It makes you look firstly at how you're treated and secondly how you treat everybody else.
它让你首先看别人怎样对待你，其次看你怎样对待别人。
《柯林斯英汉双解大词典》
No, firstly, I am superman.
不，首先，我是超人。
