If you ______ the chat room ten minutes ago, you _______ what we were talking about.

A．have joined ; will know

B．had joined ; would have known

C．should join ; would know

D．would join ; have known

关于胸主动脉瘤的特点，下列不正确的是（）

A.可以产生主动脉瓣关闭不全

B.可以引起Horner综合征

C.可以分为真性动脉瘤、假性动脉瘤和夹层动脉瘤

D.死亡原因主要是缺血性脑病

E.手术治疗是最有效的方法