150 x 60 x 200 = 1.8 mil. x 90% = 1.6 mil words covered

来源: 于 2010-03-21 14:08:29 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

50 x 200 =10,000 hours / 2000 h ( 40 h.x 50 weeks) =
5 years for those passed.
10-20 years or never for half failed.