膜内电位由+30mV变为-70mV的过程称（ ）。
A．极化
B．去极化
C．超极化
D．复极化
E．部分去极化
参考答案：D
________ you have bought the little dog, you should take good care of it instead of taking no notice of it, Nina.
A. For B. Now that C. After C. As soon as
我国现代学校产生于( )。
A．17世纪末 B．18世纪末 C．19世纪末 D．20世纪末
