心肌细胞有效不应期特别长的生理意义是

A．使心肌不发生强直收缩

B．使心肌全或无式收缩

C．使心肌收缩更有力

D．使心肌产生自动节律性兴奋

E．使心肌同步收缩

She remains optimistic (乐观的) in spite of so much hardship she has _____. [ ]

A. gone through

B. looked through

C. gotten through

D. passed through