根据激活信号的不同，离子通道可分为（）、（）和应力激活通道。
参考答案：电压门通道；配体门通道
既能疏肝破气，又能散结消滞的药物是：（ ）
A．橘皮
B．青皮
C．枳实
D．木香
E．香附
A straight pipe 1 yard in length was marked off in fourths and also in thirds. If the pipe was then cut into separate pieces at each of these markings, which of the following gives all the different lengths of the pieces, in fractions of a yard ？（）
A.A
B.B
C.C
D.D
E.E
