Today is Friday. Peter has six classes today. He goes to school at 7:30 a.m. At 8:00 a.m., he begins his first class. The first class is English. At 9:00 a.m., he has math. Peter likes math because it’s interesting. At 10:00 a.m. she has a biology class. Peter thinks it's very boring. Then at 11:00 a.m., he has a history class. That's his favorite subject. He can learn a lot about the past from history.
    Peter has lunch at school at about 12:00. Then he has a short break. At 1:30 p.m., he has a music class. At 2:30 p.m., he has a P.E. class. Peter likes this afternoon, because music and P.E. are easy and interesting. School is over at 4:00 p.m. Peter is happy because he can go home and have a good time on Saturday and Sunday.
阅读短文内容，选择正确答案。

某同学设计实验证明：酸与碱发生中和反应时有水生成。请帮助其完成实验报告：

实验操作步骤	实验现象	解释、结论与化学方程式
⑴取少量CuSO4粉末，向其中滴加几滴水	CuSO4粉末____	化学方程式： ____
⑵向盛有无水醋酸的干燥试管中加入CuSO4粉末；另取一支干燥试管，向其中加入____和____。	CuSO4粉末____	实验说明： ____
⑶将固体氢氧化钠加入盛有无水醋酸和CuSO4的试管里	CuSO4粉末____	结论： NaOH与醋酸反应有水生成

买6个羽毛球的钱，正好买一个小猪娃娃，一个小猪娃娃____元钱？

买7个魔方的钱，正好买一辆玩具汽车，一辆玩具汽车____元钱？

已知圆C₁:x²+y²+2x+8y-8=0与圆C₂:x²+y²-4x-4y-2=0相交，则圆C₁与圆C₂的公共弦所在的直线的方程为（   ）

方程|x²﹣2x|=a²+1（a∈R⁺）的解的个数是____．