我搞不懂“取非削弱”，能以此例帮我解释明白吗

我实在搞不懂“取非削弱”为何物！？能请NN以此例帮我解释明白吗

In an attempt to reduce the crime rate, the governor is getting tough on criminals and making prison conditions harsher.  Part of this effort has been to deny inmates the access they formerly had to college-level courses.  However, this action is clearly counter to the governor’s ultimate goal, since after being released form prison, inmates who had taken such courses committed far fewer crimes overall than other inmates.

Which of the following is an assumption on which the argument depends?

1. Not being able to take college-level courses while in prison is unlikely to deter anyone from a crime that he or she might otherwise have committed.

2. Former inmates are no more likely to commit crimes than are members of the general population.

3. The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.

4. Taking high school level courses in prison has less effect on an inmate’s subsequent behavior than taking college-level courses does.

5. The governor’s ultimate goal actually is to gain popularity by convincing people that something effective is being done about crime.

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你先把The group of inmates who chose to take college-level courses were not already less likely than other inmates to commit crimes after being released.的not按住，就发现，意思变成那些选择大学课程学习的罪犯在选择课程前就比其他罪犯在释放后犯罪机率要小，这就对结论inmates who had taken such courses committed far fewer crimes overall than other inmates起到了削弱的作用。

相反，如果加上not，就对结论起加强作用了。

以后碰到类似题目，你就先按住not

我的天啊，竟然写了两次，断网真郁闷啊

The reason why you need “取非削弱” is to identify the Necessary Assumption for the conclusion.  If the nessary assumption does NOT exist, then the argument is weaken.

多谢各位！哈哈

祝好～！##￥%……&