Unmanned post offices meant millions of letters went unsorted.邮局无人工作意味着许多信件无人分拣。...a special unmanned spacecraft.一架特别的无人驾驶飞行器The fare from the last unmanned station is probably less than a pound...从上一个无人站过来的费用可能还不到1镑。......
Unmanned post offices meant millions of letters went unsorted.邮局无人工作意味着许多信件无人分拣。an unmanned Mars mission无人火星探测Scientists say these unmanned flights can make important and exciting discoveries.科学家们说这次无人驾驶的太空飞行能够获得令人兴奋的重大发...