"We can detect sunspots at a depth of 60,000 kilometers, but if we try to detect them deeper or closer to the surface, the travel-time shift becomes weaker," Ilonidis says.

“我们能探测六万公里深处的黑子，但如果探测更深些或者更靠近太阳表面的位置时，(声波的)传播时间的变化将变得不明显，”Ilonidis说。

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"We can detect sunspots at a depth of 60, 000 kilometers, but if we try to detect them deeper or closer to the surface, the travel-time shift becomes weaker," Ilonidis says.

“我们能探测六万公里深处的黑子，但如果探测更深些或者更靠近太阳表面的位置时，(声波的)传播时间的变化将变得不明显，”Ilonidis说。

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This shift is due to both improved safety standards and technology as well a move away from underground mines towards surface mining and controversial mountaintop-removal mining.

这种数据上的提高在于安全标准的提升和技术的进步，同时，地表开采和富有争议性的削山开采也使得地下开采也逐渐走到地上。

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Surface represents a major shift in strategy for the Microsoft Windows business unit.

FORBES: Microsoft Announces Surface, Its New Windows 8 Tablet

Troubles arising from the so-called Millennium Bug (chips and programs that think 00 is 1900, not 2000) will surface as companies and governments shift to fiscal year 2000.

FORBES: Fact and Comment

The last to surface was Urzua, the 54-year-old shift boss.

CNN: After a final day together, miners begin to disband