问答题 当截平面垂直于圆锥轴线时，截平面与圆锥相交形成的的交线形状为：

单项选择题 You are caring for a 68-year-oldmale who has copious amounts of fluid in the left pleural cavity due to acute pleurisy. When you exam him as he sitsup in  bed (trunk upright), where wouldthe fluid tend to accumulate? A、   costodiaphragmaticrecess B、costomediastinalrecess C、  cupola D、  hilarreflection E、 middlemediastinum

单项选择题 红霉素的抗菌谱不包括（ ）A. 革兰阳性菌B. 铜绿假单胞菌C. 军团菌D. 支原体E放线菌