$ F4 ?$ [& T3 P* F3 |: `# GTheory is when you know everything but nothing works. 1 ?, {/ s5 s8 h/ w. \ 6 |1 w; U! ?* Q2 N, `: LPractice is everything works but no one knows why. 5 d2 J1 z* ?7 |/ R) k ( g) d" Y% ]" W2 ]; e! ]+ }$ b这两天的情况是:Theory and practice are combined: nothing works and no one knows why.