分解因式:x2-25=______.
x2-25=(x+5)(x-5).
故答案为:(x+5)(x-5).
词形变化:
(1) Good (lucky) to you.
(2) She is a (luck)girl. She gets the job.
(3) (luck), he didn't hurt himself badly.
Begg技术把整个矫治过程分为三期,第一期的矫治目标是()
A.打开前牙咬合,解除前牙拥挤,排齐前牙,矫正磨牙反和锁
B.关闭后牙间隙,矫正扭转的前磨牙,调整磨牙关系至Ⅰ类关系
C.获得所穷牙齿理想的倾斜度和轴倾角
D.拉尖牙向远中
E.牙位及接触关系的进一步调整