Firstly, ambition plays an essential role because it serves as a driving force for people to achieve success.

首先，志向起着至关重要的作用，因为它是人们取得成功的动力源泉。

youdao

Firstly, food is often thrown away before it reaches customers because too much of it is produced.

首先，食物经常在到达顾客之前就被扔掉，因为生产的食物太多了。

youdao

This is because of the following three reasons: Firstly, the thief only stole things from me but did not hurt me at all; secondly, the thief has stolen some of my things instead of all my things; thirdly, most luckily for me, it was the man rather than me who became a thief.

这是因为以下三个原因：第一，小偷只偷我的东西，而没有伤害我；其次，小偷偷走了我的一些东西，而不是我所有的东西；第三，对我来说最幸运的是，成为小偷的是那个人，不是我。

youdao

Firstly, because the judge in Bangladesh was prepared to go public and emphasise the "civil wrong" which had been done against her client, and secondly, because a British High Court order served under the new Forced Marriage Act was mentioned at the Dhaka hearing.

BBC: The fight against forced marriage

He said the reasons were firstly practical, because for example if a person's entitlement to vote was based on Scotland being their birthplace a whole new electoral register would be needed.

BBC: Member's debate: Independence referendum

Firstly, there is a tiny extra risk of complications because of the general anaesthetic.

BBC: Heart bypass - with local anaesthetic