is it
isn’t it
does it
doesn’t
第1题:
The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, __1__ this is largely because, __2__ animals, we stand upright. This means that our noses are __3__ to perceiving those smells which float through the air, __4__ the majority of smells which stick to surfaces. In fact, __5__, we are extremely sensitive to smells, __6__ we do not generally realize it. Our noses are capable of __7__ human smells even when these are __8__ to far below one part in one million.
Strangely, some people find that they can smell one type of flower but not another, __9__ others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate __10__ smell receptors in the nose. These receptors are the cells which sense smells and send __11__ to the brain. However, it has been found that even people insensitive to a certain smell __12__ can suddenly become sensitive to it when __13__ to it often enough.
The explanation for insensitivity to smell seems to be that brain finds it __14__ to keep all smell receptors working all the time but can __15__ new receptors if necessary. This may __16__ explain why we are not usually sensitive to our own smells we simply do not need to be. We are not __17__ of the usual smell of our own house but we __18__ new smells when we visit someone else’s. The brain finds it best to keep smell receptors __19__ for unfamiliar and emergency signals __20__ the smell of smoke, which might indicate the danger of fire.
1________________
[A] although
[B] as
[C] but
[D] while
第2题:
A.good; beautiful
B.good; beautifully
C.well; beautiful
D.well; beautifully
第3题:
what is IMO ?what is ISO 9000?what is ISM ?what is SMS system ?
第4题:
第5题:
第6题:
第7题:
第8题:
It can scent a lot of synthetic fragrance into the environment.
It is a machine which blows warm and fresh air into the environment.
It often pumps the smell of freshly-cut grass from a high-street shop.
It is a box which sends out not only aroma but also music.
第9题:
第10题:
burnt
burning
burn
is burning
第11题:
fire mask
breathing apparatus
life-jacket
fire drill
第12题:
keep up with
put up with
end up with
catch up with
第13题:
A、have polluted
B、is being polluted
C、has been polluted
D、have been polluted
第14题:
Are holds free of smell?
第15题:
第16题:
第17题:
第18题:
第19题:
the right smell made people think a product was better
people preferred the smell of lemon to coconut
certain smells could make people dislike a shop
customers rated the goods on sale as more inviting
第20题:
deer like the smell of human hair
deer can be repelled by the smell of human hair
deer die when eating human hair
deer flee at the sight of human hair
第21题:
life-jacket
fire mast
breathing apparatus
life suit
第22题:
sense
view
means
idea
第23题:
Amazing
Amazed
Amazingly
Amazedly
第24题:
together with
on top of
underneath
away from