铁树爱“吃”铁钉的原因是（）
A.体内缺锌元素
B.体内缺磷元素
C.体内缺铁元素
D.体内缺钾元素
参考答案：C
Fair and (73) competition in government procurement around the world is good business and good public policy．Competitive pricing，product (74) and performance improvements result from competitive practices and help ensure that government authorities get the best (75) for the public they serve．
A．recession B．innovation C．crisis D．ability
王国维“一代有一代文学”，“唐之诗，宋之词”，那元代的是什么？
