The first day at school is a big event in a child's life.

第一天上学在孩子的一生中是件大事。

youdao

I made the acquaintance of my best friend at the first day of my high school life.

我第一次遇见我最好的朋友是在高中生活的第一天。

youdao

The first day at the writer's new school was cold and snowy.

作者在新学校的第一天，天气寒冷，还下着雪。

youdao

He spoke on the first day of classes at a high school in Virginia.

VOA: special.2009.09.10

Referring to the rebels, state-run media blamed "terrorists" for the explosions, which occurred on the first day of exams at the school.

CNN: Moscow suspends consular operations in Aleppo

The older ones had their first day at school on June 8th and 25 of the younger ones have just started at the primary school next door, where, despite language problems, teachers say they mingle well with local children.

ECONOMIST: Kosovar refugees

And the poor fella looks like he's been given detention for forgetting his homework diary on his first day at big school when Gambhir banjaxes him through the covers for yet another boundary to bring up his fifty.

BBC: England v India as it happened