商品入库一次作业是指卸车、验收、堆码地次完成。
参考答案:对
— Whose exam paper is it?
— It _____ be Jenny's. She always forgets to write her name on it. [ ]
A. can't
B. must
C. shouldn't
正常心电图心房激动产生的波是()。
A.P波
B.Q波
C.R波
D.T波
E.U波