哥特弓描记是为了（）
A.帮助患者下颌后退
B.确定正中关系位
C.确定垂直距离
D.了解下颌运动情况
E.重复测定的客观依据
参考答案：A
When he learned that his brother had returned from abroad, he set off to his home _____. Which
of the following is not OK? [ ]
A. immediately
B. right away
C. right then
D. right now
E. at once
设f(x)在x0的邻域内三阶连续可导，且f(x0)=f"(x0)=0，
(x0)＞0，则下列结论正确的是( )
(x0)＞0，则下列结论正确的是( )