Find out the past forms of the following words in the vocabulary.

从词汇表中找出下列单词的过去式。。

youdao

Remember when you are talking about the past, you use the past forms of the verbs, e.g.

记住当你谈论过去的事情时，用动词的过去式。

youdao

Speaking of the knacks, when you know the past forms of some irregular verbs, you will find some rules.

要说窍门，在多背一些动词的不规则过去式后，你会发现还是有一些规律的。

youdao

They said they had the right to set the rates for those links, as they had set rates in the past for other forms of licensing of their intellectual property.

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The mixed-race population has increased, due to both inter-racial marriages and Census Bureau forms in the past two headcounts that allow people to identify themselves as more than one race.

WSJ: Population Leaves Heartland Behind

And we also know that several have happened in the past leading to the extinction of all higher life forms at the time.

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