—Which of these two sweaters will you take?

—I'll take              . They look nearly the same, and I just need one. [ ]

A. both

B. either

C. none

D. all

上消化道出血的临床表现最主要取决于()

A．病变部位的高低

B．出血量与出血速度

C．出血前患者全身情况

D．病变性质的良恶

E．出血时患者的抵抗力