不出现颈静脉怒张的病变是（）
A.心包积液
B.纵隔肿瘤
C.门静脉高压
D.右心衰竭
E.上腔静脉综合征
参考答案：C
免疫的功能：自身稳定：清除体内_____ 和损伤的细胞。
防御感染：抵抗________ 的侵入，防止 _______ 的产生。
免疫监视： ______ 和_____ 体内产生的异常细胞（如 ______ ）。
—How far apart do they live?
—________I know, they live in the same neighbourhood.[ ]
A. As long as
B. As far as
C. As well as
D. As often as
