She had a cold, and he had a _____, too.[ ]
A. fever
B. cold
C. stomachache
答案:B
直接指示法
对电离辐射抗性较高的三种免疫细胞是()
A.巨噬细胞
B.NK细胞
C.成熟粒细胞
D.血中B淋巴细胞
E.血中T淋巴细胞