题目内容
已知一个关系数据库的模式如下：market(mno，mname，city)、item(ino，iname， type，color)、sales(mno，ino，price)，其中，market表示商场，它的各属性依次为商场号、商场名和所在城市；item表示商品，它的各属性依次为商品号、商品名、商品类别和颜色； sales表示销售，它的各属性依次为商场号、商品号和售价。
查询长沙每个商场都销售，且售价均超过3000元的商品的商品号和商品名的SQL语句为：
SELECT ino, iname FROM item
WHERE (24)
(SELECT* FROM market
WHERE (25) AND NOT EXISTS
(SELECT*FROM sales
WHERE (26) AND price＞3000))
查询在不同的商场中最高售价和最低售价之差超过100元的商品的商品号、其最高售价和最低售价的SQL语句为：
SELECT ino, MAX(price), MIN(price)FROM sales
(27) HAVING MAX(price)-MIN(price)＞100
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A．GROUP BY mnoB．GROUP BY inoC．GROUP BY priceD．GROUP BY MAX（price)
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Task 2
Directions: This task is the same as Task 1. The 5 questions or unfinished statements are numbered 41 through 45.
Birds are warm-blooded, vertebrate animals whose bodies are covered with feathers. Other characteristics of birds are: wings; a short tail bone; the visible tail being composed entirely of feathers; a weak or nonexistent sense of smell; no teeth; and keen hearing, despite the absence of external ears. As in mammals (哺乳动物), the only other group of warm-blooded animals, the blood in the veins (静脉) of birds is kept totally separated from the blood in the arteries (动脉).
Birds evolved from reptiles, especially from some small dinosaur-relative. Gradually the scales of the dinosaur evolved into feathers, perhaps first for insulation as the animal evolved from cord to wing blade but later for flight. It is still unknown, however, whether flight developed when a ground-living form. began to flap its wings to increase its running speed (like the ostrich today), or when a tree climbing form. used imperfect wings to aid it in leaping from tree limb to tree limb. The evolution from reptile to the bird as we know it concluded about 75 million years ago, at the beginning of the Tertiary period, or age of mammals.
The earliest classification of birds relied upon easily recognized external characteristics or upon peculiarities of behavior. or appearance. For example, all web-footed birds were grouped together and all seed-eating birds were grouped together. Since the 19th century and the general acceptance of evolution, however, this method has given way to a sounder and more scientific procedure. Birds, as well as all other living things, are now classified in a way that best expresses their blood relationships and lines of descent. This kind of classification is known as a phylogenetic classification (系谱分类).
This passage is most probably taken from a ______.
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