Woman: Is the rescue crew still looking for survivors of the plane crashMan: Yes, they have been searching the area for hours, but they haven't found anybody else. They'll keep searching until night falls.Question: What do we learn from the conversation

A．All the passengers were killed.

B．The plane crashed in the night.

C．No more survivors have been found.

D．It's too late to search for survivors.

原发性高血压最常见的死亡原因是（）

A.尿毒症

B.心力衰竭

C.脑血管意外

D.高血压急症

E.高血压危象