'I have eaten' is the present perfect tense of the verb 'to eat', 'I had eaten' is the past perfect and 'I will have eaten' is the future perfect.

I have eaten是动词eat的现在完成时；I had eaten是过去完成时；I will have eaten是将来完成时。

《牛津词典》

I want to tell you about the past, present and future of the human population. So let's start with a few problems.

我想告诉你们有关人口数量的过去、现在和未来。那么让我们从一些问题入手。

youdao

I want to tell you about the past, present and future of the human population, so let's start with a few problems.

我想告诉你们关于人类的过去、现在和未来的事情，所以让我们从一些问题入手。

youdao

Or patients might be advised to think less about the past and more about the present and the future.

VOA: special.2010.04.13

Israel's past and present and future generations form a collective entity, Israel, that collectively assents to the covenant.

犹太人的过去，现在，未来形成了一个共同的存在，全体犹太人都赞成这个契约。

耶鲁公开课 - 旧约导论课程节选

And then we try and get our simulation to match the past, and hope that that will help it predict the future.

尝试让仿真程序能和这一部分实际数据相符，并且希望它能够帮我们对未来进行预测。

麻省理工公开课 - 计算机科学及编程导论课程节选

They are in the moment, free of anxiety about the past or the future.

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The question as to why 7.7% of Americans are unbanked is linked to the past and the future.

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Both the country's patterns of energy use and its attitude towards the environment point more towards the past than the future.

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