盘点的周期因盘点方法不同而不同，对于定期盘点，一般一年1～4次。
参考答案：错
--- Excuse me. Where’s the school library, please?
--- ________________
--- I asked where the school library was.
A．All right.
B．Mm, let me think.
C．What do you mean ?
D．Oh, I beg your pardon ?
* * 恶性肿瘤时视诊有何异常改变？
