We（）our breakfast when the pilot came on board.

A.just have had

B.just had

C.have just had

D.had just had

静脉注射甘露醇引起尿量增加的主要机制是

A．肾小球毛细血管血压降低

B．囊内压升高

C．血浆胶体渗透压降低

D．血浆晶体渗透压降低

E．肾小管内溶质浓度增加