Some scientists think that massive ocean extinction events in the past caused Earth's carbon cycle to fluctuate wildly for millions of years afterwards.

一些科学家认为过去大量海洋生物的灭绝，将引起数百万年后地球碳循环上下幅度变大。

youdao

Think of your favorite memories, people and events from your past and you'll see things that have shaped you into the person you are today.

回想一下那些最美好的记忆、人物和重要时刻，你就会发现一些东西，是它们影响并塑造了今天的你。

youdao

Now wI think back to the elementary school was supposed to all sorts of past events, some happy, some sad.

现在的我回想起小学的种种往事真是哭笑不得，有的让人开心，有的让人伤心。

youdao

Think back at the events and images of the past year.

UN: Secretary-General

You know, Chip, I think on the -- I think on the President's trip to California, I think there is rightly concern and outrage for the events of the past week, and there's rightly concern and frustration about the economic challenges that this country face.

WHITEHOUSE: White House Press Briefing: March 20,2009

And I think what's also very important is we have not waited for the events of the past several days to bring up our concerns and the concerns of the Egyptian people about what I said: association, assembly, freedom of expression, freedom -- Internet freedoms.

WHITEHOUSE: Press Briefing