在实数范围内分解因式:x3-x2-2x+2.
x3-x2-2x+2,
=x2(x-1)-2(x-1),
=(x-1)(x2-2),
=(x-1)(x+2)(x-2).
The student, in Jinshan Middle School for 3 years, was admitted into Qinghua University.
A.to study
B.studying
C.to have studied
D.having studied
“沸水顶壶盖”“苹果落地”这两种常人司空见惯的自然现象却引发了两位科学家的思考,并促成了两项科学发明或发现是[ ]
A.爱迪生——电灯泡、爱因斯坦――相对论
B.毕升――活字印刷术、莱特兄弟――飞机
C.哈格里夫斯――纺纱机、达尔文――进化论
D.瓦特――蒸汽机、牛顿――万有引力