在电影院内听不到回声，下列原因中正确的是 （ ）
| A．墙壁反射的声音与原声混在一起分不出来 |
| B．墙壁吸音性好，传向墙壁的大部分声音被吸收了 |
| C．墙壁吸收了全部声音 |
| D．以上说法均不正确 |
蝙蝠在黑夜能发现要捕食的昆虫，是 （ ）
| A．借助于超声波 | B．借助于复眼 |
| C．借助于红外线 | D．借助于紫外线 |
实验室制取气体选择收集方法时，对气体的下列性质不必考虑的是
| A．颜色 | B．密度 | C．溶解性 | D．是否与水反应 |
实验室制取气体选择收集方法时，对气体的下列性质不必考虑的是
| A．颜色 | B．密度 | C．溶解性 | D．是否与水反应 |
Increasingly ,over the past ten years ,people—especially young people—have become aware of the need to change their eating habits ,because much of the food they eat ,particularly processed foods ,is not good for the health .As a result ,there has been a growing interest in natural foods :foods which do not contain chemical fertilizers ,widely used in farming today .
Natural foods ,for example ,are vegetables ,fruit and grain which have been grown in soil that is rich in organic(有机的)matter . In simple terms ,this means that the soil has been nourished by unused vegetable matter ,which provides it with essential vitamins and minerals. This in itself is a natural process compared with the use of chemicals and fertilizers , the main purpose of which is to increase the amount—but not the quality—of food grown in commercial farming areas .
Natural foods also include animals which have been allowed to feed and move freely in healthy grassland for cattle .Compare this with what happens in the mass production of poultry (家禽):there are battery farms ,for example ,where thousands of chickens live crowded together in one building and are fed on food which is little better than rubbish .Chickens kept in this way are not only tasteless as food; they also produce eggs which lack important vitamins .
There are other things of healthy eating which are now receiving increasing attention from experts on diet .Take ,for example ,the question of sugar .This is actually a non-essential food! Although another natural food ,such as honey ,can be used to sweeten food if this is necessary ,we can in fact do without it .It is not that sugar is harmful in itself .But it does seem to be addictive : the quantity we use has grown steadily over the last two centuries and in Britain today each person consumes an average of 200 pounds a year !Yet all it does is provide us with energy ,in the form of calories .There are no vitamins in it ,no minerals ,and no fibre .
It’s very important that nowadays fibre is considered to be an important part of a healthy diet .In white bread ,for example ,the fibre has been removed .But it is present in unrefined flour and of course in vegetables .It is interesting to note that in countries where the national diet contains large quantities of unrefined flour and vegetables ,certain diseases are comparatively not often seen .For this reason ,the importance is placed on the eating of wholemeal(没有去麸的面粉)bread and more vegetables by modern experts on “healthy eating”.
【小题1】People have become more interested in natural foods because .
【小题2】Chickens raised in poultry farms are all of the following EXCEPT that .
【小题3】According to the passage,_________.
Natural foods ,for example ,are vegetables ,fruit and grain which have been grown in soil that is rich in organic(有机的)matter . In simple terms ,this means that the soil has been nourished by unused vegetable matter ,which provides it with essential vitamins and minerals. This in itself is a natural process compared with the use of chemicals and fertilizers , the main purpose of which is to increase the amount—but not the quality—of food grown in commercial farming areas .
Natural foods also include animals which have been allowed to feed and move freely in healthy grassland for cattle .Compare this with what happens in the mass production of poultry (家禽):there are battery farms ,for example ,where thousands of chickens live crowded together in one building and are fed on food which is little better than rubbish .Chickens kept in this way are not only tasteless as food; they also produce eggs which lack important vitamins .
There are other things of healthy eating which are now receiving increasing attention from experts on diet .Take ,for example ,the question of sugar .This is actually a non-essential food! Although another natural food ,such as honey ,can be used to sweeten food if this is necessary ,we can in fact do without it .It is not that sugar is harmful in itself .But it does seem to be addictive : the quantity we use has grown steadily over the last two centuries and in Britain today each person consumes an average of 200 pounds a year !Yet all it does is provide us with energy ,in the form of calories .There are no vitamins in it ,no minerals ,and no fibre .
It’s very important that nowadays fibre is considered to be an important part of a healthy diet .In white bread ,for example ,the fibre has been removed .But it is present in unrefined flour and of course in vegetables .It is interesting to note that in countries where the national diet contains large quantities of unrefined flour and vegetables ,certain diseases are comparatively not often seen .For this reason ,the importance is placed on the eating of wholemeal(没有去麸的面粉)bread and more vegetables by modern experts on “healthy eating”.
【小题1】People have become more interested in natural foods because .
| A．they want to keep fit |
| B．they want to taste all kinds of foods |
| C．natural foods are more delicious than processed foods |
| D．they want to return to nature |
| A．they are fed on food which is little better than garbage |
| B．they live in very crowed condition |
| C．the eggs they produce lack vitamins |
| D．they are allowed to move about and eat freely |
| A．people need sugar to give them energy |
| B．sugar is bad for the health |
| C．the use of sugar is habit forming |
| D．sugar only sweetens food, but provides us with nothing useful |
黄色皱粒豌豆（Yyrr）与绿色圆粒豌豆（yyRr）杂交，后代表现型之比近于 （ ）
| A．9:3:3:1 | B．3:1:3:1 | C．1:1:1:1 | D．3:1 |
“长三角”地区已经初步形成了以上海为中心、南京和杭州为副中心的“长三角”大都市圈城市体系。读图，回答问题。
【小题1】图中南京都市圈中的城市按等级可分为
【小题2】有关城市规模与服务功能的叙述，正确的是
【小题1】图中南京都市圈中的城市按等级可分为
| A．二级 |
| B．三级 |
| C．四级 |
| D．五级 |
| A．常州市的服务范围较南京市大 |
| B．宁海县提供的服务种类较台州市多 |
| C．杭州市与台州市的服务范围不可能重叠 |
| D．泰州市和镇江市城市服务功能基本相同 |
把锌、铜分别放入其他两种金属X、Y的盐溶液中，实验结果如下表，其中“
”
表示能反应，“
”表示不反应。
上述四种金属的活动性由强到弱的顺序是
0 65685 65693 65699 65703 65709 65711 65715 65721 65723 65729 65735 65739 65741 65745 65751 65753 65759 65763 65765 65769 65771 65775 65777 65779 65780 65781 65783 65784 65785 65787 65789 65793 65795 65799 65801 65805 65811 65813 65819 65823 65825 65829 65835 65841 65843 65849 65853 65855 65861 65865 65871 65879 235360
”表示能反应，“
”表示不反应。上述四种金属的活动性由强到弱的顺序是
| A．X、Y、Z、Zn、Cu | B．Y、Zn、X、Cu |
| C．X、Zn、Y、Cu | D．X、Cu、Zn、Y |
