I was unable to attend because of a previous engagement.

我因有约在先，无法出席。

《牛津词典》

I am unable to attend because of a previous engagement.

我因有约在先故不能出席。

youdao

I'd love to, but I'm afraid I have a previous engagement.

我很宁愿答应往，但生怕已跟他人事前有约。

youdao

The tennis star broke off a previous engagement earlier this year.

BBC: Pakistani cricketer Shoaib Malik 'divorces first wife'

This level of customization was not available in its previous games and it is very likely that it will increase user engagement, leading to higher revenues from advertising and in-game purchases.

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