解：（1）∵二次函数y=ax²+bx的图象经过A（1，﹣1）、B（4，0）两点，

∴$a+b=-116a< 同类题1 通过下列实验操作和现象能得出相应结论的是（   ）实验操作现象结论A向收集满 CO2的软塑料瓶中加入约13体积滴有石蕊试液的水，旋紧瓶盖，振荡塑料瓶变瘪， 　溶液变红CO2能与石蕊反应B往CuSO4和FeSO4的混合溶液中加锌粉反应后过滤，在滤渣中滴加稀盐酸有气泡滤渣中一定有Cu和Fe，可能有ZnC在某无色溶液中滴加氯化钡溶液有白色沉淀无色溶液中一定含有Ag+离子D把质量相同的镁条与锌粒同时放入相同浓度和体积的盐酸中镁条与盐酸产生气体更快 镁的金属活动性比锌强 同类题2 如图，D是AB的中点，E是BC的中点，BE= 15 AC=3cm，求线段DE的长． 同类题3 阅读下面短文, 掌握其大意, 然后从每题所给的A、B、C、D四个选项中选出最佳选项, 使文章完整, 通顺。       Nobody in the street knew Miss Hilton. While she lived, her front gate was always locked and no one ever saw her 1 or saw 2 go in. So even if you 3, you couldn't feel sorry and 4 that you 5 Miss Hilton.    When I think of 6, I see just two colours, grey and green. The green of mango tree, the grey of the house and the grey of the high iron fence（铁栅栏） that kept you off the mangoes.    If your football 7 Miss Hilton's garden, you never 8. It wasn't the mango season 9 Miss Hilton died. But we got back about ten 10 twelve of our footballs.    11 the end of the week a sign was shown on the mango tree: For sale.    We were ready to dislike 12 even before they came. I think we 13. Already we had one man who kept on complaining（抱怨）about us 14 the police. He complained that we played football near his house and if we weren't playing football he complained that we were making 15 noise anyway. 同类题4      完形填空    I'll tell you1about my English teacher, Mrs. Wang. She is a middle-aged woman. She is not tall and not short , and she is also not2and not thin . She3long black hair. She likes4a red dress. She is very beautiful. She5very good English . She has three classes a week , but they aren't6Tuesday or Friday. All the students in her class love her very much.    Mrs. Wang lives not7the school. She walks to school with her son and her daughter early every morning. Her two children are8.They look the same. They are in Grade Two, but they are not in9class . They often wear the same clothes. They look very10. 同类题5 战国时期，秦国在成都地区修建的著名水利工程是____；秦统一后修建的沟通长江和珠江水系的水利工程是____。 小学学科试题库 小学语文 小学数学 小学英语 小学科学 小学道德与法治 初中学科试题库 初中数学 初中语文 初中英语 初中物理 初中化学 初中生物 初中政治 初中历史 初中地理 初中历史与社会 初中科学 初中信息技术 高中学科试题库 高中语文 高中数学 高中英语 高中物理 高中化学 高中生物 高中政治 高中历史 高中地理 高中信息技术 刷题宝 没有分数是刷题提高不了的！ 粤ICP备12066032号 本站仅为免费收集试题提供给学生刷题，不做任何盈利性活动！如无意侵犯您的合法权益，联系站长删除处理（QQ:2572127418） $