一些汽車上有一個后備輪胎，如果有哪個輪胎爆了，可以隨時更換；大型噴氣式飛機(jī)也有后備的機(jī)械設(shè)備，如果在飛行中出現(xiàn)機(jī)械故障的話，馬上換用后備設(shè)備可以保證繼續(xù)安全飛行；連球隊(duì)都有后備隊(duì)員，看來“后備”在我們的現(xiàn)代生活中真是很重要。
Back-up system 就是指這種后備的設(shè)施。我們來看個例子：航天飛機(jī)的內(nèi)部有好多后備的設(shè)備來保護(hù)宇航員，
On the second day of the flight, the space shuttle's main air-conditioning system broke down. But the astronauts switched on the back-up system and were able to continue the mission for another three days and land safely at Edwards Air Force Base.
在航天飛機(jī)起飛后的第二天，飛機(jī)里的空調(diào)設(shè)備壞了。宇航員于是開動了后備的空調(diào)設(shè)備，這樣他們才能再持續(xù)工作三天,然后安全地在愛德華茲空軍基地降落。
在當(dāng)前高技術(shù)極為普遍的時代，如果沒有后備的設(shè)施，有的時候非但會影響工作，而且還會造成很大的危險(xiǎn)。下面就是一個例子：
This airline pilot talked about getting ready to land that famous day when all the lights in New York went out. He said he was lucky the airport had a back-up system of its own generators -- otherwise he would have to try to land in total darkness.
大家都知道紐約發(fā)生停電，全城陷入黑暗的那一天。這個飛行員談到當(dāng)天他準(zhǔn)備降落的情景。他說，幸運(yùn)的是，機(jī)場自己有后備的發(fā)電設(shè)備。否則，他得設(shè)法在黑暗里降落。"
（改編自：美國習(xí)慣用語 英語點(diǎn)津 Annabel 編輯）
Back-up system 就是指這種后備的設(shè)施。我們來看個例子：航天飛機(jī)的內(nèi)部有好多后備的設(shè)備來保護(hù)宇航員，
On the second day of the flight, the space shuttle's main air-conditioning system broke down. But the astronauts switched on the back-up system and were able to continue the mission for another three days and land safely at Edwards Air Force Base.
在航天飛機(jī)起飛后的第二天，飛機(jī)里的空調(diào)設(shè)備壞了。宇航員于是開動了后備的空調(diào)設(shè)備，這樣他們才能再持續(xù)工作三天,然后安全地在愛德華茲空軍基地降落。
在當(dāng)前高技術(shù)極為普遍的時代，如果沒有后備的設(shè)施，有的時候非但會影響工作，而且還會造成很大的危險(xiǎn)。下面就是一個例子：
This airline pilot talked about getting ready to land that famous day when all the lights in New York went out. He said he was lucky the airport had a back-up system of its own generators -- otherwise he would have to try to land in total darkness.
大家都知道紐約發(fā)生停電，全城陷入黑暗的那一天。這個飛行員談到當(dāng)天他準(zhǔn)備降落的情景。他說，幸運(yùn)的是，機(jī)場自己有后備的發(fā)電設(shè)備。否則，他得設(shè)法在黑暗里降落。"
（改編自：美國習(xí)慣用語 英語點(diǎn)津 Annabel 編輯）