丹参的抗心肌缺血作用是由于（）
A.扩张冠状动脉，增加血流量
B.促进钙内流
C.开放钙通道
D.开放钠通道
E.以上均不是
参考答案：A
系统分析的首要任务是【 】。
It is reported that________ created by a world famous artist will be on show here in 14 days.
A．scores of work
B．scores of works
C．score works
D．score of work
