A.有豐富的血管和神經(jīng)末梢 B.無(wú)血管無(wú)神經(jīng)末梢 C.有血管無(wú)神經(jīng)末梢 D.無(wú)神經(jīng)末梢 E.無(wú)血管有豐富的神經(jīng)末梢