从业务流程的实体角度看，物流活动中的采购业务是一种______。
A．组织内流程
B．跨组织流程
C．部门内流程
D．个人间流程
参考答案：B
负责把RNA转录成互补DNA分子的（）酶可以解释由（）引起的永久性基因转变。
—I don't know _______ to do with this letter. May I give it to our teacher?
—I don't think so. You'd better not do it like this. [ ]
A. what
B. where
C. how
D. why
