对齿轮传动的基本要求是：传动要（），承载能力大。
参考答案：平稳
The new manager is intelligent and hard-working, and___________, he is very charming.
A．instead
B．therefore
C．however
D．moreover
痰浊壅塞之胸痹的特点是
A．胸闷如窒而痛B．胸痛彻背，感寒痛甚C．胸部刺痛，固定不移D．胸闷隐痛，时作时止E．心胸隐痛，痛无定处
