【多选题】在 神经干动作电位 引导的实验中可观察到
A.
神经干动作电位呈双相性,向上的波和向下的波幅度一定相等
B.
神经干动作电位的幅值会在一定范围内随刺激强度的增大而增大
C.
如果将两引导电极之间的神经夹伤,观察到的为单相动作电位
D.
改变引导电极 两端之间的 距离动作电位的时程不变
【单选题】Scott arrived at the South Pole on January 18 th , only ______ that Amundsen had got there before him.
【简答题】轴的尺寸为 E,则其验收极限按 内缩方式确定,上验收极限为( )mm,下验收极限为( )mm。
【单选题】Scott arrived at the South Pole on January 18th, only __________ someone had been there before him.
【判断题】I. Spring A. temperature B. color C. implication of life II. Autumn A. color B. temperature C. implication of life III. Winter A. temperature B. implication of life C. color
【单选题】A company exports 50 tons of wheat, the seller delivers the extra 2 tons, then the buyer should ( ).
B.
refuse to take 52 tons
D.
refuse to accept extra 2 tons