①5.66-0.96÷6×5
②4.12×6.9-4.12+4.12×1.1
③(1÷0.2+0.2÷1)÷(6-0.8)
④(4.3-0.52)÷3.6+6.4
⑤1.4÷(0.14×0.25)
⑥1.2-1.2×[0.01÷(1-0.9)]