The United States Food and Drug Administration(FDA) regulates the introducation of new therapeutic agents into the marketplace. Consequently, it plays critical role in improving health care in the Unitied States. Whilt it is those in the academic and government research communities who engage in the long process of initial discovery and clinical testing of new therapeutic agents, it is the FDA's role and responsbility to facilitate the transfer of new discoveries from the laboratory to the marketplace. Only after the transfer can important new therapies help patients.

(B)Before new therapeutic agents reach the marketplace they do not help patients.

(E)if a new medical discovery has been transferred from the laborratory to the marketplace, it will help patients.

问题只要集中在这两个选项上.

我选E,答案是B.看了解释但是感觉很牵强.不知道哪位能指点小弟我一下?

题来自陈向东的(GMAT逻辑推理)

谢谢.

注意最后的only

after A，B：A－－－》B

only after A，B：B－－>A(即一般情况下没B，只有当有A 的时候才有B，则有

B一定有A。)

E的推倒方向反了。

我想是的

但不是only after 而是only的存在

ONLY A then B

A then B

是不同的推倒方向我想。

only的存在使得方向颠倒了

即B存在，必定after A。

而 A then B，即【after A】－－>B