引起上消化道出血最常见的原因是（）。
A.胃癌
B.胃十二指肠溃病
C.肝硬化
D.出血性胃炎
E.胆道出血
参考答案：B
—Can you go to the mall with me this Sunday?
—Sure, ________. [ ]
A. I'd love to.
B. I'm sorry. I can't.
C. OK.
D. Oh, no.
—Who is Mozart?
—______ is a musician. [ ]
A. He
B. She
C. Her
D. Him
