8 r: b0 {4 I; }* j6 a& YTheory is when you know everything but nothing works. 4 ?! d; ~, @; j. }% |; U$ ` , Z! p; Q) f4 q% F+ vPractice is everything works but no one knows why. S$ E& d0 A) k5 o- c2 r" i / Z" ^( q+ w! x0 X这两天的情况是:Theory and practice are combined: nothing works and no one knows why.