男性，28岁，水肿、少尿1周，2周前有"感冒"史，BP150／90mmHg，HGB80g／L，尿蛋白（+++），尿隐血（+++），尿红细胞15～20个／HP，血肌酐384μmol／L，B超示左肾11．1cm×4．1cm×5．2cm，右肾12．2cm×4．8cm×5．4cm，下一步首选的方案是（）

A.给予泼尼松龙冲击治疗

B.给予泼尼松龙冲击治疗+细胞毒类药物

C.抗感染治疗+血液透析

D.肾穿刺后再定方案

E.先保守治疗，动态观察肾功能，根据情况再定

According to the author, swans in captivity are ______.

A．happy unless their wings have been cut

B．happy most of the time, but unhappy sometimes

C．unhappy most of the time

D．only happy when they are bringing up families