转盘实际上是一个伞形齿轮减速器，它将发动机的水平旋转运动通过传动机构及减速机构变为转台的（）.
参考答案：垂直旋转运动
---Why not come and join us in the game, Linda?
--- ______, but I have something to discuss with Mr. Smith at his office now.
A．Let’s go
B．I’d like to
C．Yes, please
D．It’s a pleasure
下列哪种抗生素治疗痤疮有效
A．青霉素类
B．四环素或红霉素类
C．头孢菌素类
D．抗真菌类
E．氨基糖苷类
