Throughout history man has had to accept the fact that all living things must die, but people now live longer than they used to．Yet, all 1 things still show the effect of aging, which will eventually 2 death．The body and the 3 they form do not function as well as they 4 in childhood and adolescence(青春期)．The body provides less 5 against disease and is more prone(易于……的) 6 accident．
A number of related causes may 7 to aging．Some cells of the body have a 8 long life, but they are not 9 when they die．As a person ages, 10 of brain cells and muscle cells decreases．Other body cells did and are replaced by new cells．In an aging person the 11 cells may not be as viable(能生存的)or as capable 12 growth as those of a young person．
Another factor in aging may be changed within the cells 13 ．Some of the protein chemicals in cells 14 known to change 15 age and become less elastic．This is why the skin of old people wrinkles and hangs loose．This is also the reason old people shrink in 16 ．There may be other more important chemical changes in the cells．Some complex cell chemicals, 17 DNA and RNA, store and 18 information that the cells need．Aging may 19 this process and change the information carrying molecules 20 they do not transmit the information as well．
(1)
[ ]
A．
living
B．
natural
C．
lively
D．
lovely
(2)
[ ]
A．
result in
B．
result from
C．
end in
D．
conclude
(3)
[ ]
A．
hands
B．
brains
C．
organs
D．
legs
(4)
[ ]
A．
made
B．
did
C．
grew
D．
had
(5)
[ ]
A．
prevention
B．
protection
C．
strength
D．
vitamin
(6)
[ ]
A．
of
B．
to
C．
with
D．
at
(7)
[ ]
A．
contribute
B．
compare
C．
strength
D．
be drown
(8)
[ ]
A．
fairly
B．
little
C．
more
D．
less
(9)
[ ]
A．
repeated
B．
replied
C．
replaced
D．
rearranged
(10)
[ ]
A．
the amount
B．
any amount
C．
the number
D．
a number
(11)
[ ]
A．
remaining
B．
other
C．
old
D．
new
(12)
[ ]
A．
of
B．
to
C．
with
D．
for
(13)
[ ]
A．
themselves
B．
itself
C．
by themselves
D．
of themselves
(14)
[ ]
A．
is
B．
are
C．
was
D．
were
(15)
[ ]
A．
with
B．
within
C．
for
D．
on
(16)
[ ]
A．
height
B．
high
C．
heighten
D．
higher
(17)
[ ]
A．
as such
B．
as that
C．
as though
D．
such as
(18)
[ ]
A．
pass on
B．
pass by
C．
pass into
D．
pass off
(19)
[ ]
A．
cancel
B．
affect
C．
benefit
D．
damage
(20)
[ ]
A．
so that
B．
providing that
C．
in case
D．
if
Reading comprehension
The word conservation has a thrifty(节俭)meaning．To conserve is to save and protect, to leave what we ourselves enjoy in such good condition that others may also share the enjoyment．Our forefathers(祖先)had no idea that human population would increase faster than the supplies of raw materials; most of them, even until very recently, had the foolish idea that the treasures were“limitless”and “inexhaustible”．Most of the citizens of earlier generations knew little or nothing about the complicated, and delicate system that runs all through nature, and which means that, as in a living body, an unhealthy condition of one part will sooner or later be harmful to all the others．
Fifty years ago nature study was not part of the school work; scientific forestry was a new idea; timber was still cheap because it could be brought in any quantity from distant woodlands; soil destruction and river floods were not national problems; nobody had yet studied long- term climatic cycles in relation to proper land use; even the word“conservation”had nothing of the meaning that it has for us today．
For the sake of ourselves and those who will come after us, we must now set about repairing the mistakes of our forefathers．Conservation should, therefore, be made a part of everyone’s daily life．To know about the water table in the ground is just as important to us as a knowledge of the basic arithmetic formulas．We need to know why all watersheds need the protection of plant life and why the running current of streams and rivers must be made to benefit the soil fully before they finally escape to the sea．We need to be taught the duty of planting trees as well as of cutting them．We need to know the importance of big, mature trees, because living space for most of man's fellow creatures on this planet is figured not only in square measure of surface but also in cubic volume(立方)above the earth．In brief, it should be our goal to restore as much of the original beauty of nature as we can．
(1)
The author’s attitude towards the present situation in the use of natural resources is ________．
[ ]
A．
positive
B．
neutral
C．
suspicious
D．
critical
(2)
According to the author, the greatest mistake of our forefathers was that ________．
[ ]
A．
they had no idea about scientific forestry
B．
they had little or no sense of environmental protection
C．
they did not know the importance of nature study
D．
they had no idea of how to make good use of raw materials
(3)
With a view to correcting the mistakes of our forefathers, the author suggests that ________．
[ ]
A．
we plant more trees
B．
we be taught environmental science, as well as the science of plants
C．
environmental education be directed toward everyone
D．
we return to nature
(4)
What does the author imply by saying“living space is figured also in cubic volume above the earth”(paragraph 3)?
[ ]
A．
Our living space on the earth is getting smaller and smaller in volume．
B．
Our living space should be measured in cubic volume．
C．
We need to take some measures to protect space in volume．
D．
We must create better living conditions for both birds and animals．
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