Gilbert综合征是
A．肝细胞对胆红素结合缺陷
B．肝细胞对胆红素排泄障碍
C．胆道阻塞
D．肝细胞对胆红素转运缺陷
E．红细胞破坏过多
参考答案：D
冷哮咳痰特点（）。
A.臭脓痰
B.痰稠黄胶粘
C.痰稀薄多沫，咯吐不爽
D.痰如白沫量多
E.痰黄白相兼
A competitive firm will tend to expand its output as long as marginal:（）
A. revenue is greater than marginal cost.
B. revenue is greater than the average cost.
C. cost is less than average cost.
