所谓事故频发倾向，是指个人容易发生事故的、稳定的、个人的（）倾向。
A.主动
B.被动
C.外在
D.内在
参考答案：D
This passage has too many long sentences. I’m afraid they will be hard for most of the students. Could you help to _______ them?
A．simplify
B．take
C．destroy
D．mix
呕血最常见的原因是（）
A.胃底、食管静脉曲张破裂
B.食管癌
C.消化性溃疡
D.钩端螺旋体病
E.急性胃黏膜病变
