引起成人缺铁性贫血的最主要原因是()。
A.青少年生长发育
B.妇女妊娠或哺乳
C.慢性失血
D.胃大部切除术后
E.食物中供铁不足
参考答案:C
--How long ___________ each other before they__________ married?
--For about a year.
A.have they known;get
B.did they know; were going to get
C.do they know;are going to get
D.had they known; got
发行者给予购买出版物数量较多的消费者一定的价格优惠,这种促销形式属于( )。
A.间接销售
B. 折价销售
C.现场综合促销
D.有奖销售