(Ⅰ)求证: {1xn} 是等差数列;
(Ⅱ)当x1= 12 时,求x100.
——A new museum in Shenyang in May.——Great! Let's go and visit it this summer.
如图2的四幅图中,属于利用热传递改变物体内能的是( )
下列物质在氧气中燃烧,能生成白色固体的是( )