Whose scarf is it?[ ]
A. It's mine scarf.
B. It's your scarf.
C. It's her.
答案：B
已知a，b是方程x2+6x+4=0的两个不相等的实数根，则a+b=______．
右心衰竭和肝硬化主要鉴别点是（）
A.低白蛋白血症
B.水肿
C.腹腔积液
D.颈静脉怒张，肝颈静脉回流征（+）
E.黄疸
