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【单选题】
假设一种鱼类资源从 3 岁以上开始遭受捕捞,捕捞死亡率是自然死亡率的 2 倍,已知年存活率 = 未被捕捞的资源存活率 2 ( 未捕捞时自然死亡率 30%) ,那么,这种资源三年后捕捞死亡率是 ( )A.
17%
B.
34%
C.
49%
D.
51%
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【单选题】The end sentence of the article is to ______.
A.
emphasize the importance of love
B.
explain how people love each other
C.
show why lovers exchange rings
D.
tell a story of rings in the universe
【单选题】The author's intention in writing the article is to make Americans realize that ______.
A.
it is dangerous to ignore their foreign friends
B.
it is important to maintain their leading role in world affairs
C.
it is necessary to use several languages in public places
D.
it is time to get acquainted with other cultures
【简答题】The purpose of the article is to explain_________
【单选题】The purpose of the article is to draw public attention ______ the problem.
A.
to
B.
on
C.
in
D.
for
【单选题】The aim of the article is to _____.
A.
show how to use smart cards.
B.
show the difference between ATM card and chip card.
C.
how the smart cards have become popular.
D.
persuade Americans to use smart cards.
【单选题】The purpose of the article is to tell us ______.
A.
the effect of antibiotics
B.
not to use antibiotics unless necessary
C.
that antibiotics are harmfull
D.
that our natural defence systems are superior to antibiotics
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