1:(2 + 10 ÷ 7) × 72:(2 + (10 ÷ 7)) × 73:7 × (2 + 10 ÷ 7)4:7 × (2 + (10 ÷ 7))5:7 × (10 ÷ 7 + 2)6:7 × ((10 ÷ 7) + 2)7:(10 ÷ 7 + 2) × 78:((10 ÷ 7) + 2) × 7 可能有重复,自己...