急性白血病发病病因不包括 （）
A.病毒感染
B.细菌感染
C.化学物质长期接触
D.细胞毒性药物
E.电力辐射
参考答案：B
If you are in the zoo, remember not to touch or go near the animals. Although some of the animals are cute, you _________ leave them alone.
A．must
B．will
C．may
D．can
有一病人颈部能触及一肿块，可能患什么病，病史及检查注意什么
