第27题: [单项选择]高等植物的花的主要结构是（） A. 花托 B. 花萼 C. 花蕊 D. 柱头 参考答案:C 答案解析:花是生殖器官，花蕊里产生配子，是主要结构，C正确。
考点：花的结构及作用，意在考查考生识记所学知识的要点。
第28题: [填空题]S8 参考答案:It is only more recently that it has become increasingly understood that the production of goods is a waste of resources unless those goods can be sold at a fair price．
答案解析:Main Points：Until recently people have begun to know that it is a waste of resources to produce good
