A) Give an estimate of how long its debris will stay in space.

A) 估计其碎片将在太空中停留多长时间。

So basically we are giving an estimate of what we think we will sell.

所以基本上我们是在估计我们认为我们会卖什么。

And then they double-checked by doing some more radioactive uranium and electron spin resonance dating on a fossilized tooth, which gave an estimate of 286,000 years.

然后，他们通过对一颗牙齿化石进行一些更具放射性的铀和电子自旋共振测年来进行复核，估计其存在时间为 286,000 年。

Steve said that the proposal would need to show revenue projections for the first five years, and that I should give an estimate of gross sales for that same period.

史蒂夫说提案需要显示前五年的收入预测，而我应该给出同期的总销售额估算值。