In order not to get into trouble, advertisers are increasingly cautious about taking out ads ______(aim) at children.

上皮组织的特点具备：（）。

A.有丰富的血管和神经末梢

B.无血管无神经末梢

C.有血管无神经末梢

D.无神经末梢

E.无血管有丰富的神经末梢