It is difficult to ______ a conversation with someone who only says "Yes" and "No". [ ]

A. keep up

B. take up

C. make up

D. pick up

以下哪个观点不是通道亚型的划分根据？（）

A.激活电位阀值

B.失活特性

C.药理学敏感性

D.通道所处的细胞种类