It takes around 2.5 seconds for a radio signal to reach the Moon and bounce back to another part of the Earth, so it took around five seconds to get a reply.
一道无线电讯号得花大约2.5秒传到月球，然后再回传到地球另一端，所以要收到回应大约要花5秒。
It takes around 2.5 seconds for a radio signal to reach the Moon and bounce back to another part of the Earth, so it took around five seconds to get a reply.
一道无线电讯号得花大约2.5秒传到月球，然后再回传到地球另一端，所以要收到回应大约要花5秒。
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