My mother made a ________ with the salesgirl and brought down the price of the fruit. [    ]

A. bargain 

B. choice  

C. difference  

D. promise

引起Ⅰ型呼吸衰竭最常见的疾病是（）

A.慢性支气管炎

B.阻塞性肺气肿

C.气管异物

D.膈肌麻痹

E.ARDS