词汇 firstly 在中文的含义

Firstly, I want to thank everyone for coming.

首先，我要感谢大家的到来。

We need to consider several factors: firstly, the cost; secondly, the time; and thirdly, the resources.

我们需要考虑几个因素：首先是成本；其次是时间；第三是资源。