What ____________ they doing ? [ ]
A. are
B. is
C. am
答案：A
I found her ______ in thought.
A．losing
B．lost
C．lose
D．being lost
哪种临床表现对诊断急性肾炎最有意义（）
A.水肿
B.血尿
C.高血压
D.尿比重减低
E.中等量以上的蛋白尿
