In our school library, there       a number of books on science and the number of the books        growing larger and larger.

A．is, are

B．are, is

C．have, is

D．are, are

关于免疫耐受的叙述哪项是正确的

A．产生免疫耐受后对各种Ag均不应答

B．免疫耐受无记忆性

C．免疫耐受就是免疫抑制

D．产生自身耐受是自身免疫病的起因

E．对病毒感染免疫耐受的机体易发生该病毒的疾病