问狒狒逻辑第12题

leepee

原题:12. The only physical factor preventing a human journey to Mars has been weight. Carrying enough fuel to propel a conventional spacecraft to Mars and back would make even the lightest craft too heavy to be launched from Earth. A device has recently been invented, however, that allows an otherwise conventional spacecraft to refill the craft’s fuel tanks with fuel manufactured from the Martian atmosphere for the return trip. Therefore, it is possible for people to go to Mars in a spacecraft that carries this device and then return.
Which one of the following is an assumption on which the argument depends?
(A) The amount of fuel needed for a spacecraft to return from Mars is the same as the amount of fuel needed to travel from Earth to Mars.
(B) The fuel manufactured from the Martian atmosphere would not differ in composition from the fuel used to travel to Mars.
(C) The device for manufacturing fuel from the Martian atmosphere would not take up any of the spaceship crew’s living space.
(D) A conventional spacecraft equipped with the device would not be appreciably more expensive to construct than current spacecraft typically are.
(E) The device for manufacturing fuel for the return to Earth weighs less than the tanks of fuel that a conventional spacecraft would otherwise need to carry from Earth for the return trip.

答案是E,我想不通的是尽管制造出来的返回燃料可能重量会大于从地球上带过去的返回燃料,但是由于去的时候已经燃烧了一部分燃料,比带过去的总燃料轻就能说明问题.....我觉得E并不充分

[此贴子已经被作者于2006-9-28 23:42:35编辑过]

leepee

呜呜~~怎么没人理呀，哪位大牛帮我解答一下好不好

cattsky

The only physical factor preventing a human journey to Mars has been weight. Carrying enough fuel to propel a conventional spacecraft to Mars and back would make even the lightest craft too heavy to be launched from Earth. A device has recently been invented, however, that allows an otherwise conventional spacecraft to refill the craft’s fuel tanks with fuel manufactured from the Martian atmosphere for the return trip. Therefore, it is possible for people to go to Mars in a spacecraft that carries this device and then return.
Which one of the following is an assumption on which the argument depends?
(A) The amount of fuel needed for a spacecraft to return from Mars is the same as the amount of fuel needed to travel from Earth to Mars.
(B) The fuel manufactured from the Martian atmosphere would not differ in composition from the fuel used to travel to Mars.
(C) The device for manufacturing fuel from the Martian atmosphere would not take up any of the spaceship crew’s living space.
(D) A conventional spacecraft equipped with the device would not be appreciably more expensive to construct than current spacecraft typically are.
(E) The device for manufacturing fuel for the return to Earth weighs less than the tanks of fuel that a conventional spacecraft would otherwise need to carry from Earth for the return trip.

注意画线部分:太重而不能从地球发射(launch).

发射都发射不了了,你所说的途中燃烧一些燃料减轻重量就不能成立了.

leepee

好人呀，谢谢cattsky MM的解答！

不过这个题还是有点想不通，既然发射都发射不了，那么制造出来的燃料跟返回的燃料也就没什么好比较呀

cattsky

文中强调的是燃料和device(燃料转换器)的比较

leepee

thanks a lot, i'm understood

i find my mistake is due to the incorrect reading comprehension.