肿瘤的细胞信号转导异常有（）。
A.生长因子分泌过多
B.生长因子受体过度激活
C.Ras持续激活
D.抑制细胞增殖的信号减弱
E.以上都是
参考答案：E
— How long have your parents _____?
— For 20 years. [ ]
A. got married
B. married
C. been married
批零件有195个，徒弟每天加工6个，徒弟加工一天后，师傅来帮忙加工，师傅每天能加工 7.5个。还要几天才能全部加工完？
