免疫耐受
参考答案：是指机体免疫系统在一定条件下接受某种抗原作用后产生的特异性免疫无应答状态，也称负免疫应答。
Whitman has made radical changes in the form of poetry by choosing free verse as his medium of expression. What are the characteristic of Whitman’s free verse
下列常用建筑内部装修材料的燃烧性能为B1级的有()。
A.玻璃
B.纸面石膏板
C.矿棉装饰吸声板
D.天然石材
E.瓷砖
