The spines of sea urchins can generate a voltage when water moves around them — a phenomenon that could be used to design underwater flow sensors.
One reason for routinely launching GPS satellites is simply "constellation replenishment," said Col. Andrew Menschner, deputy commander of the Space Force's Space Systems Command. Old satellites degrade and die, and new ones need to go up and replace them. At least 24 GPS satellites are needed for global coverage, and having additional satellites in the fleet can improve navigation precision. Today, there are 31 GPS satellites in operational service, flying more than 12,000 miles (20,000 kilometers) above the Earth.
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而 MacBook 那个比鼠标还好用的触控板，不仅基础的拖动点击都指哪打哪，还支持各种实用的手势，某种程度也承担了触控屏的作用。
A surge in claims