设f（x）=ax²+bx+2是定义在1+a，2上的偶函数，则f（x）的值域是____．

阅读短文，判断正误。

    Lily and Mary are good friends. They come to the park on Sunday morning.

    The park is beautiful. There are many flowers. Lily is very happy. She wants to take some flowers home. But Mary says, “We can't pick flowers.” “It don't matter.” Lily says. So she picks many flowers.

    Lily wants to show them to Mary. But Mary is not there. A moment later, Mary comes back with a man .Lily is fined(罚款）$10 for picking the flowers. The man says, “Everyone should obey the rules and protect the flowers and grass. They are our friends.”Lily is very sorry now.

请你设想一下，假如有一天，导体真的没有电阻了，我们的生活会出现哪些和现在不一样的现象？请至少说出两点？

综合性学习。
七年级学生开展以“品质富阳•文明出行”为主题的综合实践活动，活动中有一些问题，请你运用语文知识参与解决。

小强同学对镁带及其燃烧进行如下的探究后，要填写如下实验报告，请协助他：
（1）从一条镁带上折下一段，观察到断面处为银白色，镁带外观为灰黑色，用砂纸打磨后，露出银白色金属。
结论：镁带是一种具有____色金属光泽的固体
（2）用打磨好的镁带连接一节干电池和小灯泡，观察到小灯泡亮了。
结论：镁带具有____ 性。
（3）点燃镁带，燃烧后移到石棉网上方，观察到①镁带剧烈燃烧，发出____，②放出热量，③生成____ 色粉末状固体。其中能证明该变化是化学变化的现象是____（填序号）
结论：请写出该反应的文字表达式：____ 。
（4）利用镁带燃烧时产生的现象，请举一例镁粉的用途____。