One day in class, the teacher held up an apple.

一天在课堂上，老师举起一个苹果。

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One day in class, the teacher told everyone to turn to a blank sheet of paper in their notebooks.

一天，在课堂上，老师叫大家完成一个小任务--把笔记本翻到一张空白页。

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One winter day in 1891, a class at a training school in Massachusetts, U.S.A, went into the gym for their daily exercises.

1891年冬季的一天，美国马萨诸塞州一所培训学校的一个班走进体育馆进行日常训炼。

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And he--one day this boy showed up in the class-- this was during Vichy, about 1943, maybe it's '44, and he's new and he's not different, he's just not from there.

他,有一天班里来了个新同学,当时是维西政府时期,1943年,也可能44年,他是新来的也没什么特别之处,只是不是当地人

耶鲁公开课 - 1871年后的法国课程节选

Healy stopped Brewster in the hallway one day after class, with the seedling of an idea for selling electricity back to a grid, something he had chewed over with his father.

FORBES: Magazine Article

Opener Cosgrove made 1, 187 runs in first-class cricket this season, plus 959 in one-day cricket, pipping Tom Maynard and Jim Allenby to the player of the year award.

BBC: Batsman Mark Cosgrove hopes for new Glamorgan deal

Opener Cosgrove made 1, 187 runs in first-class cricket that campaign, plus 959 in one-day cricket, pipping Tom Maynard and Jim Allenby to the player of the year award.

BBC: Mark Cosgrove wants to return to his Glamorgan 'home'