这使人们确信天文周期已经存在了数十亿年。
It assures that the astronomical cycles have been in existence for billions of years.
例如，当美国在1848年获得新墨西哥的主权时，大草原就已经存在了。
For example, the Rio Grande pueblos already existed when the United States acquired sovereignty over New Mexico in 1848.
虽然我们不知道这其中有多少是真实的，但可以肯定的是，丝绸栽培在中国已经存在了几千年。
While it is unknown just how much of this is true, it is certainly known that silk cultivation has existed in China for several millennia.
根据最近的一项调查，尽管网上零售已经存在了大约20年，但近一半的网上零售商仍然没有收到满意的消费者反馈。
Although online retailing has existed for some twenty years, nearly half of the internet retailers still fail to receive satisfactory feedback from consumers, according to a recent survey.
它在那里已经存在了350多年。
电动汽车已经存在了超过一百年。
Electric vehicles have been around for more than a hundred years.
它已经存在了几百年了。
美国本土语言在欧洲殖民以前就已经存在了，现在美国已经丢失了超过三分之一的本土语言。剩下的192种语言被联合国教科文组织列为介于“不安全”和“灭绝”之间。
The US has already lost more than a third of the native languages that existed before European colonization, and the remaining 192 are classed by UNESCO as ranging between "unsafe" and "extinct".
我们假定此目录已经存在了。
在思考了一会之后，他说已经存在了。
而且已经存在了多种成熟的XQuery产品。
SQL存储过程已经存在了，它们是可重用的资产。
The SQL stored procedures already exist and are available as reusable assets.
世界上的金字塔已经存在了很长一段时间。
知道么？3d技术已经存在了100多年了！
Did you know that 3d technology has been around for over 100 years?
伊伊马尼山的冰川估计已经存在了成千上万年了。
The glaciers on Illimani are estimated to have been there for thousands of years.
实际上，您可能犯的很多错误以前就已经存在了。
In truth, many of the mistakes that you're likely to make have been made before.
这些很多问题都已经存在了20年，但是它们仍然还存在。
Many of these issues have been around for twenty years but they're still there.
但是技术已经存在了，有人注意到，其他厂商也在生产MP3播放器。
But the technology already existed, someone else notes — other people were making MP3 players.
其它文化学院已经存在了很长一段时间，并且更为深入人心。
Other cultural institutes had been here for a longer time and were more rooted.
而且这种比轻量级的以文档为中心的格式更加轻巧的格式已经存在了。
And it turns out that such lighter-than lightweight document-centric formats exist.
当我要写一个网站的时候，我总是采用已经存在了的开源程序。
When building a new site I almost always use pre-existing open source code.
您可能需要创建helloworld目录，但父目录可能已经存在了。
You will likely have to create the helloworld directory, but the parent directories will already be there.
这些趋势已经存在了好几十年，并在2000年之后愈演愈烈。
These trends have accelerated since 2000, but they have been in place for decades;
防弹背心已经存在了数十年，但是防弹皮肤还仅存于科幻小说中。
Bullet proof vests have been around for decades but skin that can stop them has only been the preserve of science fiction.
汽车厂商通过与社区一起工作来推出新的品牌，这种模式实际上已经存在了。
A car company could take an existing brand and work with the community that already exists around it.
汽车是由不同的零部件组成的，它们在车组装好之前就已经存在了。
Cars are made up of parts that existed before the car itself existed.
汽车是由不同的零部件组成的，它们在车组装好之前就已经存在了。
Cars are made up of parts that existed before the car itself existed.
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