糖尿病酮症酸中毒的表现错误的是 （）
A.酮体生成过多
B.水肿
C.治疗前，血钾偏高或正常
D.携氧功能障碍
参考答案：B
Which of the following most accurately describes a market structure that has one seller of a specific, well-defined product that has no good substitutes（）
A. Oligopoly.
B. Monopoly.
C. Monopolistic competition.
______是一种能由P、V操作所改变的整型变量。
