许多抗癌药通过干扰癌细胞DNA或RNA代谢过程而发挥疗效，其药物作用机制属于（）。

A.理化反应

B.作用于细胞膜的离子通道

C.影响生理物质转运

D.对酶的影响

E.影响核酸代谢

No one is      island. We share the world with parents, friends, teachers and classmates. Most of the time, we get on well with each other. But sometimes we disagree as well.

A. the

B. an

C. a