心交感神经对心肌效应的主要机制是
A. 心肌细胞膜上Ca2+通道开放概率增加
B. 减慢自律细胞4期的内向电流
C. 使复极相K+外流减慢
D. 增加肌钙蛋白的Ca2+亲和力
E. 不应期延长
Forty percent of cancer patients in Britain don't see a specialist because______.
A. they don't have enough money to do so
B. the healthcare system compels them to do so
C. there're too many patients waiting to see a specialist
D. there're not enough specialists for all the cancer patients
Since we have no objection to this item, let's pass on to the next on the______.
A. alternation
B. agenda
C. accord
D. algebra
诊断类风湿性关节炎正确的是
A. 晨僵至少每日半小时(≥6周)
B. 2个或2个以上关节肿胀(≥6周)
C. 非对称性关节肿胀(≥6周)
D. RF阳性(滴度＜1:32)
E. 腕、掌指、近指关节肿(≥6周)
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