苦参碱型生物碱抗心律失常作用可能包括的环节是()
A、降低自律性
B、减慢传导
C、阻断钙通道
D、阻断ß受体
E、延长动作电位时程
参考答案:A, B, D
Despite such a big difference in towards what one eats,there is no doubt that people in the west regard the Chinese food as something special.
A.point
B.idea
C.attitude
D.sight
在使用显微镜时,当下降镜筒的时候,眼睛一定要注视着_________,以免将_________ 压坏。