化为同分母是：9/12,7/12,8/12,9/12,8/12.从大到小依次是：3/4=75/100>2/3=8/12>7/12
3/4=225/300.7/12=175/300.2/3=200/300.75/100=225/300.8/12=200/300.
3/4 = 9/12,7/12 = 7/12，2/3 = 8/12，75/100 = 3/4 = 9/12,8/12 = 8/12
现在吗
