8 l! I# l* a' }" S( h4 XTheory is when you know everything but nothing works. 5 @' n7 ~% L4 V" k1 A3 X6 N. e ) \; b0 M: i1 z0 jPractice is everything works but no one knows why. ! |2 k0 n( G6 B6 R' n9 n1 e# f 4 Q( h2 w/ X" W# }" e7 l) ?这两天的情况是:Theory and practice are combined: nothing works and no one knows why.