I bought toothpaste during a buy-one-get-one-free sale.

我在买一送一的特价时买了牙膏。

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I went out today and bought a tube of toothpaste.

我今天出去买了一管牙膏。

《柯林斯英汉双解大词典》

I bought my children bubble gum flavored toothpaste.

我给孩子们买来带泡泡糖香味的牙膏。

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