下列哪种情况使氧解离曲线右移（）
A.CO2分压增高
B.CO2分压降低
C.pH升高
D.温度降低
E.2，3-DPG浓度降低
参考答案：A
—The winner of the race is a tall and thin boy with glasses.
—Then it _______ be my friend, Tom, who looks like a "ball". [ ]
A. mustn't
B. can't
C. may
D. should
( )，是指合同当事人双方权利和义务共同指向的事物。
A．对象 B．主体 C．标的 D．质量
