1. (2020五上·曲靖期末) 脱式计算，能简算的要简算。

①17.05-1.3-8.7+12.95

②0.32×2.5×12.5

③2.78×1.1-2.78

④16.1÷0.23-23.65

⑤5.04×3.7+3.7×3.96+3.7

⑥23.6÷[（6.8-5.4）×2.75-0.9]