第2题: [单项选择]全口义齿人工后牙的近远中总长度应等于该侧 A. 尖牙近中面至磨牙后垫前缘的距离 B. 尖牙远中面至磨牙后垫前缘的距离 C. 尖牙远中面至磨牙后垫1/3处的距离 D. 尖牙远中面至磨牙后垫1/2的距离 E. 尖牙远中面至磨牙后垫后缘的距离 参考答案:B 答案解析:全口义齿人工后牙的近远中总长度应小于或等于该侧尖牙远中面至磨牙后垫前缘的距离。第二磨牙远中面应位于磨牙后垫前缘。
第11题: [单项选择]Lack of technological progress in the ancient and medieval worlds was primarily due to the absence of ______. 参考答案:D 答案解析:合理的社会组织结构，在第三句话“there was a still greater obstacle to change until the very end of the middle ages:
第35题: [单项选择]His inability to learn foreign languages was a(n) obstacle to his career. A. barrier B. excess C. carrier D. impulse 参考答案:A 答案解析:[解析] 本题中，obstacle的意思是“障碍，妨害物”。四个选项中，barrier的意思是“障碍”，如：The police put a barrier across the road．(警察设了
