A:正极为Cu,负极为Fe,电解质溶液为Fe(NO3)2溶液
B:正极为Cu,负极为Fe,电解质溶液为FeCl3溶液
C:正极为Fe,负极为Zn,电解质溶液为Fe2(SO4)3溶液
D:正极为Ag,负极为Fe,电解质溶液为CuSO4溶液
Mr. Smith is from England. He teaches French in our school. His English classes are very interesting. He likes us and we like him.Mr. Smith has two children--Tom and Mary. Tom is seven and his sister Mary is four. Tom goes to school but Mary doesn't. Mr. Smith likes to wear a T-shirt and jeans. Football is his favorite sport. After school we often have a basketball game. Sometimes Mr. Smith watches and plays basketball with us. He plays basketball just for fun .
已知点P(x0,y0)和直线y=kx+b,则点P到直线y=kx+b的距离证明可用公式d= |kx0−y0+b|1+k2 计算.
例如:求点P(﹣1,2)到直线y=3x+7的距离.
解:因为直线y=3x+7,其中k=3,b=7.
所以点P(﹣1,2)到直线y=3x+7的距离为:d= |kx0−y0+b|1+k2 = |3×(−1)−2+7|1+k2 = 210 = 105 .
根据以上材料,解答下列问题:
创新作文
生活,像一个百宝箱,里面盛放着生活中的酸甜苦辣咸,有甜蜜的回忆,有温馨的留念,当然也有痛苦的回忆,内疚的片段。
请以“人,无论谁都有一两件感到后悔的事”,作开头,结合自己的切实生活感受,写一篇记叙文。
要求:(1)自拟题目;(2)以记叙为主,要写出真情实感;(3)全文不少于500字,不多于600字;(4)文中涉及的区域、单位、姓名,均用××代替,自己的姓名统一用“明明”代替,否则不给分。