题目内容
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The use of chemicals and fertilizers in farming is meant to increase ______.
A．the quantity of foods
B．the quality of foods
C．either the quantity or the quality of foods
D．the quality as well as the quantity
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更多“The use of chemicals and ferti…”相关的问题
Questions are based on the following passage．
According to a report from the Harvard School of Public Health， many everyday products， including some bug sprays and cleaning fluids， could lead to an increased risk of brain and behavioral disorders in children．The developing brain， the report says， is particularly （36） to the toxic effects of certain chemicals these products may contain， and the damage they cause can be （37） ．
The official policy， however， is still evolving．Health and environmental （38） have long urged U．S．government agencies to （39） the use of some of the 11 chemicals the report cites and called for more studies on their long-term effects．In 2001， for example， the Environmental Protection Agency（40）the type and amount of lead that could be present in paint and soil in homes and child-care （41）， after concerns were raised about lead poisoning．The agency is now （42）the toxic effects of some of the chemicals in the latest report．
But the threshold for regulation is high．Because children"s brain and behavioral disorders， like hyperactivity and lower grades， can also be linked to social and genetic factors， it"s tough to pin them on exposure to specific chemicals with solid （43）evidence， which is what the EPA requires．Even the Harvard study did not prove a direct（44）but noted strong associations between exposure and risk of behavioral issues．
Nonetheless， it"s smart to（45）caution．While it may be impossible to prevent kids from drinking tap water that may contain trace amounts of chemicals， keeping kids away from lawns recently sprayed with chemicals and freshly dry-cleaned clothes can"t hurt．
A．advocates
B．compact
C．correlation
D．exercise
E．facilities
F．interaction
G．investigating
H．overwhelmed
I．particles
J．permanent
K．restricted
L．simulating
M．statistical
N．tighten
O．vulnerable
第（36）题选
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Foods which do not contain chemical additives (添加剂) and which have not been affected by 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 foods grown in commercial farming areas.
Natural foods also include animals which have been allowed to feed and move freely in healthy pastures(牧场). Compare this with what happens in the mass production of poultry: there are 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 lay eggs which lack important vitamins.
There are other aspects 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! Al though a natural alternative, such as honey, can be used to sweeten food if it 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 to provide us with energy, in the form. of calories. There are no vitamins in it, no minerals and no fiber.
It is significant that nowadays fiber is considered to be an important part of a healthy diet. In white bread, for example, the fiber 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 rare. Hence the emphasis is placed on the eating of whole meal bread and more vegetables by modem experts on "healthy eating".
People have become more interested in natural foods because ________.
A．they are more health conscious
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.medicines
B.chemicals
C.toiletries
D.magazines
A．has worked
B．works
C．has been working
D．is working
Night of the Living Ants
When an ant dies，other ants move the dead insect out of the nest．This behavior. is interesting to scientists，who wonder how ants know for sure-and so soon-that another ant is dead．
Dong-Hwan Choe，a scientist at the University of California，found that Argentine ants have a chemical on the outside of their bodies that signals to other ants，“I’m dead-take me away．”
But there's a twist to Choe's discovery．Choe says that the living ants-not just the dead ones -have this death chemical．In other words，while an ant crawls around，perhaps in a picnic or home，it's telling other ants that it's dead．
What keeps ants from hauling away the living dead？Choe found that Argentine ants have two additional chemicals on their bodies，and these tell nearby ants something like，“Wait-I'm not dead yet．” So Choe's research turned up two sets of chemical signals in ants：one says，“I'm dead，”the other set says，“I'm not dead yet．”
Other scientists have tried to figure out how ants know when another ant is dead．If an ant is knocked unconscious，other ants leave it alone until it wakes up．That means ants know that unmoving ants can still be alive．
Choe suspects that when an Argentine ant dies．the chemical that says“Wait-I'm not dead yet” quickly goes away．Once that chemical is gone，only the one that says“I'm dead”is left．“It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard(墓地)，not because its body releases new，unique chemicals after death，”said Choe．When other ants detect the“dead”chemical without the“not dead yet”chemical，they haul away the body．This was Choe's hypothesis(假设)．
To test his hypothesis，Choe and his team put different chemicals on Argentine ant pupae(蛹)． When the scientists used the“I'm dead”chemical，other ants quickly hauled the treated pupae away． When the scientists used the“Wait-I'm not dead yet”chemical，other ants left the treated pupae alone． Choe believes this behavior. shows that the“not dead yet”chemical overrides(优胜于)the“dead”chemical when picked up by adult ants．And that when an ant dies，the“not dead yet”chemical fades away． Other nearby ants then detect the remaining“dead”chemical and remove the body from the nest．
The phrase“this death chemical”in paragraph 3 refers to
A．the chemical that contains poison．
B．the chemical that announces death．
C．the chemical that prevents death．
D．the chemical that causes death．
A.used to
B.is used to
C.use
D.use to
— Terribly sorry to interrupt, but may I use your dictionary？
— Yes,______________.
A: of course
B; it doesn’t matter
C; no hurry
A.Of course not.
B.You’re welcome to use it.
C.It doesn’t matter.
D.Why？
