计算①÷[×(+)] ②(0.4+)÷(﹣0.75)×0.5③1.25+×7.4+125%÷ ④⑤6.6﹣÷(0.375×+×0.8) ⑥﹣2.125+(4.75﹣)⑦+[(1.5+)÷3.75﹣]÷ ⑧+++…+.