虽然可以排除其他答案选D，但是有一点比较疑惑：
关于Manned spaceflight ，文中只提到compete economically with---，好象与impediment没有多大关系。怎样的思路才能认为d是对的？
18. Teresa: Manned spaceflight does not have a future, since it cannot compete economically with other means of accomplishing the objectives of spaceflight.
Edward: No mode of human transportation has a better record of reliability: two accidents in twenty-five years. Thus manned spaceflight definitely has a positive future.
Which of the following is the best logical evaluation of Edward’s argument as a response to Teresa’s argument?
(A) It cites evidence that, if true, tends to disprove the evidence cited by Teresa in drawing her conclusion.
(B) It indicates a logical gap in the support that Teresa offers for her conclusion.
(C) It raises a consideration that outweighs the argument Teresa makes.
(D) It does not meet Teresa’s point because it assumes that there is no serious impediment to transporting people into space, but this was the issue raised by Teresa.（D） (E) It fails to respond to Teresa’s argument because it does not address the fundamental issue of whether space activities should have priority over other claims on the national budget. | 
