简便计算
①70.8﹣1.25﹣1.75          ②5.81+8.3+4.19+11.7        ③3.54×0.29﹣0.29×2.54 
④0.25×17.3×0.4           ⑤7.2×9.9                  ⑥48×0.69+3.1×4.8．