对于二次三项式x2+2ax+a2这样的完全平方式,我们可以用公式法将它分解因式成(x+a)2的形式,但是,对于二次三项式x2+2ax-3a2,就不能直接用完全平方公式进行分解因式了,我们可以在二次三项式x2+2ax-3a2中先加上一项a2,将其配成完全平方式,再减去a2这项,使整个式子的大小不变,于是有
x2+2ax-3a2=x2+2ax+a2-a2-3a2=(x+a)2-4a2=(x+a+2a)(x+a-2a)=(x+3a)(x-a).利用上述方法把m2-6m+8分解因式.
阅读下列短文，从每小题的四个选项中选出最佳选项
A
There are too many cities around the world. And each city needs water in many ways. Water on Earth falls mainly as rain. So the rainfall (降雨量) is important to each part of the world. And it is different from one city to another. The following chart shows the average (平均的) rain fall in four different cities in July and January.
City
Guangzhou
London
Washington
Paris
Country
China
Britain
America
France
Rainfall in July
227.6mm
45.0mm
96.5mm
53.6mm
Rainfall in January
43.2mm
78.0mm
69.1mm
54.3mm
《蚊子和狮子》一文中“粘”的读音是____；“不料”的含义是____。
吉林省“大学生诚信就业公益大讲堂”在师大举行。这是吉林省大学生诚信就业“百千万”工程自启动以来的第十场。
回答下列小题。
