Permuted Block Randomization 医药临床实验中的随机数的产生； Block可以为定值：2 或者是随机2或4（推荐使用）-Permuted Block Randomization medicine clinical trials of the random numbers generated Block can set the value: 2 or a random 2 or 4 (recommended)

临床医药试验随机数的产生（Biased Coin Randomization)-Clinical medicine test the generated random number (Biased Coin Randomization)