兴奋性
参考答案：
指机体组织或细胞接受刺激后发生反应的能力或特性。
2. ---- English, as a living language, ________ all the time.
---- Right. Who knows what it will be like in the years to come?
A．will change
B．is changing
C．was changing
D．has changed
清筛机在运行前须在驾驶室内对换挡手柄进行怎样的转换？
