问题:对取非的一点疑惑

jkzlg

1) 对于一些复杂句不知在那一部分取非: 如下句
Not being able to take college-level courses while in prison is unlikely to deter anyone from crime that he or she might otherwise have committed.
是对谓语is unlikely取非吗?
2) 经常听说:正面不能证明A导致B,则证非A导致非B...其实在CR中,A是指选项, B是指结论吗?还是说在某个选项里存在的AB关系.
比方说GWD-12-Q11加强题:
In general, jobs are harder to get in times of economic recession because many businesses cut back operations.  However, any future recessions in Vargonia will probably not reduce the availability of teaching jobs at government-funded schools.
This is because Vargonia has just introduced a legal requirement that education in government-funded schools be available, free of charge, to all Vargonian children regardless of the state of the economy, and that current student-teacher ratios not be exceeded.
答案: During recent periods when the Vargonian economy has been strong, almost 25 percent of Vargonian children have attended privately funded schools, many of which charge substantial fees.
解释那里说可通过非A推非B得出. 我就不懂这里的A和B指什么.
麻烦各位大牛解答!!!!

jkzlg

但是我不知道在本题中非A和非B分别指什么:
In general, jobs are harder to get in times of economic recession because many businesses cut back operations.  However, any future recessions in Vargonia will probably not reduce the availability of teaching jobs at government-funded schools.
This is because Vargonia has just introduced a legal requirement that education in government-funded schools be available, free of charge, to all Vargonian children regardless of the state of the economy, and that current student-teacher ratios not be exceeded.
答案: During recent periods when the Vargonian economy has been strong, almost 25 percent of Vargonian children have attended privately funded schools, many of which charge substantial fees.

sdcar2010

I think you meant: 正面不能证明A导致B,则证非B导致非A.

jkzlg

那第2题呢???有没有人知道????

sdcar2010

Negate the verb.

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