2024届江苏省南通市高三第一次调研（南通一模）化学试卷及参考答案,答案汇总网收集关于2024届江苏省南通市高三第一次调研（南通一模）化学试卷及参考答案的相关科目试卷及其答案，更多其他试卷答案请关注本网站！
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One possible versionSeveral minutes later, the ice broke suddenly and Harry's feet sank into the water. It was noep, but his legs got wet to the knees. Harry was so upset that the accident would delay hisschedule. He had to find some firewood to build a fire to dry his clothes. He pulled off his glovestook out his matches, and lighted the fire. Seeing the burning fire, he had thought he was safe. Butsuddenly, without warming, a heavy mass of snow dropped down. The flame of hope was put outUnluckily, his dog ran away and the fear of death came over Harry. He had no choice but torun to save himself. However, he did not feel his feet when they hit the ground. Having falleneveral times, he decided to rest a while. As he lay in the snow, he noticed he was not shaking. Hecould not feel his nose or fingers or feet. A feeling of horror came into his mind. It was when herealized he was going to die that he heard a bark and the noise his friends made
20.解:设调配A型卡车x辆,B型卡车y辆,0≤x≤8,0≤y≤4,则x,y满足{x+y≤10,(4分)4×6x+3×10y≥180,x,y∈N0≤x≤80≤y≤4,整理得到x+y≤10,(6分)4x+5y≥30,x,y∈N设运费为z则z=320x+504y,(7分)不等式组对应的可行域如图所示:x+y-10024x+5y=3中12343678910x考虑动直线320x+504y-z=0,其斜率为k=因为4x+5y=30与x轴的交点为(7.5,0),(8分)故当动直线320x+504y-x=0过(7.5,0)附近的整点(7,1)或(8,0)时可取最小值当x=7,y=1时,z=2744;当x=8,y=0时,z=2560,(10分)故调配A型卡车8辆,B型卡车0辆时,费用最低且最低费用为2560元(12分)
21解:(1)a,b为正实数,不等式g+b等价于由b)2a2+b2所以,当且仅当a=b时取等号(4分)(2)①直角三角形ABC的两条直角边分别为a,b,则斜边c=√a2+b2,其周长为a+b+c=√2+1(6分)由(1)的结论,(a+b)+c≤2所以2+1≤2c+c,所以2+1≤2c+c,所以斜边c≥1.(8分)②由①斜边c≥1,得a+b≤2,(10分)面积为S1a=2(2121/a+ba=b=时取等号,所以直角三角形ABC面积的最大值为4·(12分)
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