急性胰腺炎患者如果呕吐频繁可引起（）
A.代谢性碱中毒
B.代谢性酸中毒
C.呼吸性碱中毒
D.呼吸性酸中毒
E.混合性酸中毒
参考答案：A
—Sorry, I'm late.
—It's OK. However, you________come to the company today, for it is Saturday. [ ]
A. couldn't have
B. needn't have
C. wouldn't
D. couldn't
给你一只盛着水的烧杯，请你用它们设计两个物理小实验，并简要说明实验的原理．（如需其他器材可以自行选用）
