为增强嵌体修复的固位力,下列哪项是错误的
A.利用鸠尾固位形
B.轴壁上利用沟固位形
C.加大洞缘的斜面
D.适当加深洞形
E.髓壁上利用钉洞固位形
参考答案:C
It is often ____ that human beings are naturally equipped to speak.
A.said
B.to say
C.saying
D.being said
洋金花来源于茄科植物白花曼陀罗的干燥()。