定时减法计数.输入数据0到9之间三位数, 开始计时, 每秒减一.Input data between the three - digit 0 - 9, start running, by one per second.还初步确定了肝特异性F抗原 的分子量为43KD,等电点在6.7～6.9之间.Ag has an apparent molecular weight of 4.3 kD with esoelectric point of 6...