关于抗原，错误的说法是（）

A.能显示抗原性和免疫原性的抗原称完全抗原

B.抗原性是指抗原与抗体起反应的特性

C.免疫原性是指抗原能诱发特异性免疫反应的特性

D.具有抗原性的分子一定具有免疫原性

E.半抗原只显示抗原性而无免疫原性

We all think that _____ no need to make laws to prevent the young from getting married during their college life.

A．it is

B．there has

C．it has

D．there is