解方程:x2-6x+1=0.
x2-6x=-1.
x2-6x+9=-1+9,
(x-3)2=8,
x-3=±8,
x1=3+22,x2=3-22;
通过抑制前列腺素合成而起到消炎止痛作用的药物称()
A.非甾体抗炎药
B.DMARD
C.选择性COX-2的抑制剂
D.非选择性COX抑制剂
E.糖皮质激素
According to our school regulations, you _____ arrive at school before 7 A.M.
A. may B. can C. will D. should