机体排斥微生物侵袭的能力属于下列哪一种免疫功能()。
A.免疫识别
B.免疫防御
C.免疫自稳
D.免疫监视
E.免疫排斥
参考答案:B
He gave me a map, which proved to be of great ________ while I got round Beijing. [ ]
A. price
B. cost
C. value
D. charge
斜巷冒顶应怎样维修?