6. Damaged nerves in the spinal cord do not regenerate themselves naturally, nor even under the spur of nerve-growth stimulants. The reason, recently discovered, is the presence of nerve-growth inhibitors in the spinal cord. Antibodies that deactivate those inhibitors have now been developed. Clearly, then, nerve repair will be a standard medical procedure in the foreseeable future.

Which of the following, if true, casts the most serious doubt on the accuracy of the prediction above?

(A) Prevention of the regeneration of damaged nerves is merely a by-product of the main function in the human body of the substances inhibiting nerve growth.

(B) Certain nerve-growth stimulants have similar chemical structures to those of the antibodies against nerve-growth inhibitors.无关比较点

(C) Nerves in the brain are similar to nerves in the spinal cord in their inability to regenerate themselves naturally.无关比较点

(D) Researchers have been able to stimulate the growth of nerves not located in the spinal cord by using only nerve-growth stimulants.（A）无关

(E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.可以解决的

论据：抑制物抑制神经再生， 结论：发现抗体，可实现神经再生，问削弱

一直没想明白A为何是削弱 是如何削弱的呢

谢谢

Discussed before.

Let me give you an example: eating make people sick. Therefore, people

should stop eating to prevent sickness. Weaken: eating is critical for

people to sustain, or, making people sick is just a by-product of

eating.

虽然差不多明白了题目的意思，不过又觉得这道题的结论不好，结论是nerve

repair will be a standard medical procedure in the foreseeable future，

似乎改成adding such antibodies to human body will be a standard medical

procedure in the foreseeable future更好，不知道大家的看法怎样？？？