平面圆柱齿轮传动可分为:直齿、()、齿轮齿条、斜齿轮、人字齿轮转动。
参考答案:内啮合
为使固定桥充分发挥咀嚼功能,除哪项外均需要()
A.良好的固位、稳定
B.缺隙区牙槽嵴丰满
C.基牙稳固、支持力强
D.恢复缺失牙的形态和咬合关系
E.设计合理
_____ the story is short and there are no new words in it, it is difficult to understand. [ ]
A. Because
B. Although
C. Since
D. While