In the Oral Approach, Palmer insisted that there was a basic difference between the spontaneous capacities of human beings to ______ language naturally and unconsciously and the trained or"situational" capacities of the classroom learner which allowed him to learn language consciously.

下列哪项不是广地龙的性状特征（）

A.呈长条状薄片，弯曲

B.全体具环节，背部棕褐色至紫灰色，腹部浅黄棕色

C.第14～16环节为生殖带，习称"白颈"

D.受精囊孔3对，在6/7～8/9环节间

E.体轻，略呈革质，不易折断