①12.5×3.7×0.8                           
②4.6×2.3+7.7×4.6
③3.6+（5.7+3.8）÷0.5                     
④3.6÷0.4﹣1.5×3
⑤0.1÷0.2÷0.4                       
⑥80.3﹣5.6×1.7．