可引起上腹部疼痛的疾病是（）
A.急性胰腺炎
B.急性心肌梗死
C.急性肺炎
D.急性胆囊炎
E.带状疱疹
参考答案：A, B, C, D, E
---Do you know Miss Tang?
---Yeah, she is an excellent teacher, ______she is famous ______a wonderful singer in our school.
A．or; for
B．but; as
C．and; for
D．so; as
离心泵发生汽蚀后，易造成吸人管阻力（）。
A.减小
B.不变
C.消失
D.增大
