What do you think of Harbin and Qingdao in winter? I think Harbin is ______ than Qingdao.[ ]

A. interesting

B. the most interesting

C. much interesting

D. much more interesting

学习和记忆的电生理学基础是

A．识记、保持，再认和回忆

B．胆碱能神经元动作电位

C．内流钙离子

D．突触长时程增强电位

E．经典条件反射