患者女性，30岁。既往健康，突然咯血约500ml。查体：心肺未见异常，胸部X线片示双肺下野纹理增粗。

该患者可能的诊断是（）。

A.急性支气管炎

B.支气管扩张症

C.支气管内膜结核

D.支气管肺癌

E.急性肺梗死

F.慢性肺脓肿

Jack said that he was sure of succeeding in passing the Totel Examination this time, _______, in my opinion, I don’t think so.

A．what

B．which

C．but

D．therefore