影响血中游离钙浓度的主要因素是
A.体温
B.血液pH值
C.血浆球蛋白浓度
D.血磷浓度
E.血红蛋白浓度
参考答案:B
结合英国革命具体史实,试归纳英国资产阶级革命的特点,并分析其具备这些特点的原因有哪些。
Sally looks very happy. She ________ have got the first place in the 200metre race.[ ]
A. should
B. could
C. must
D. might