1. (2020五上·雅安期末) 计算下面各题．

①2.5×71.71×0.4

②1.25×9.93﹣1.93×1.25

③30.16﹣30.16÷5.8﹣4.8

④17.55+15.2+0.576÷0.12

⑤47.4﹣1.65×（18.8+3.2）

⑥0.36÷[0.8×（6.1﹣4.6）]