43：A：even old decimal nine minus twenty divide sceond third Fifth twelfthB1)1000 2008 860 410 302)315 19 37 893)1/5 3/4 2/94)41% 75% 53%5)41° 32.5°180°60°6）31.13 0.42 67.88 7.77 9.8 只能帮到43...