question from Feifei

hahahahaha09

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.

 choose E, i understand, but why B is not correct

please help

hahahahaha09

哪个NN,能给说说啊

lufangyuan77

我也觉得这题很奇怪。
我的理解是B可能有些无关了。

但是问题在于E也不一定绝对对。我理解传统航天器飞不上天的主要原因是太重了。
那既然新式装备可以在返程之前制造燃料。那我只要带一半油上去就行了。回来的油到时再说嘛。
但是新造的没必要一定要比那会的时候来的轻啊。

答案的解释我感觉关键还是看NEGATE的方法。E确实相对最合适了。

棒棒dudu

阻碍人们上火星的主要原因就是fuel的重量 而不是它的材料