红细胞内2,3-DPG增多可引起
A. 动脉血氧饱和度增加
B. 血红蛋白与氧的亲和力增加
C. 血液携带氧的能力增加
D. 红细胞向组织释放氧增多
E. 细胞利用氧的能力增加
My father now pays great attention to his ________.
A. weight
B. might
C. tight
D. hold
________ exercise is fit for many people.
A. Over
B. Plenty
C. Aerobic
D. High
My grandparents are quite______ and they travel from time to time.
A. stayi
B. search
C. grasp
D. healthy