科学家们并不知道大部分这些中型小行星的地址，估计有15,000颗中型小行星地址不详。

Scientists also don't know where most of these midsize ones are - there are an estimated 15, 000 midsize asteroids left to locate.

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相当大量的数据存储在云中心，服务器的地址不详。

And a vast amount of data is stored in the cloud, on servers whose location may be unknown.

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这类炸弹实质上是发送地址不详、数量巨、容量庞大、充满乱码或没有意义的垃圾邮件，大多数时候通过大量重复发送信件来实现。

This kind of bomb is actually send out from unknown address, great amount, huge capacity, full of chaos codes and nonsense mails. Most of the time send away same mail repeatedly.

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