短波紫外线照射皮肤后出现红斑的潜伏期是几小时
A.1.5~2h
B.3~4h
C.6小时以上
D.2~3h
E.4~6h
参考答案:A
I __________ a teacher. He __________ a policeman. They __________ doctors. [ ]
A. am; is; are
B. am; is; is
C. is; is; are
能抑制肿瘤细胞的生长又能刺激其细胞运动的因子是().
A.AMF
B.EGF
C.IL-1
D.肝细胞生长因子
E.TGF