The statistics experts generated randomized serial numbers（001-296）according to same-size allocation ratio between arm A and arm B with Statistical Analysis System 9.2(SAS 9.2), a statistical software in the randomized block method. The serial numbers are the randomized grouping numbers for the trial patients, block capacity is 8, totally 37 randomized block. One copy send to trial centers for patient allocating, and the another copy be saved by the trial applicant unit. Every trail centers will be responsible for the screening of qualified patients, rank them in visit time to get the randomized grouping number so as to determine them goes to arm A or arm B .The research people and patients in all trial centers should not know the randomized grouping number and relevant arms. The arm name will be sealed under scratch card. Every trial patients will get a unique randomized number, and it will not change through out the whole trial.