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【简答题】
是乳糖不耐症的原因是一部分人随着年龄增长,消化道内缺乏____而不能分解和吸收____,饮用牛乳后会出现呕吐、腹胀、腹泻等不适应症。当____活性低或缺乏时,____在肠道内不分解而直接进入大肠,使大肠渗透压增高,导致水分进入肠道管腔内,大肠中细菌繁殖,产生乳酸和CO2,至pH下降,当pH<6.5时刺激大肠,引起腹痛、腹泻。
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【简答题】{a n }是等差数列，a 2 =-1，a 8 =5，则数列{a n }的前9项和S 9 =______．
【简答题】在等差数列{a n }中，a 1 =1，a 5 =9，在数列{b n }中，b 1 =2，且b n =2b n-1 -1，（n≥2） （1）求数列{a n }和{b n }的通项公式； （2）设 T n = a 1 b 1 -1 + a 2 b 2 - 1 + a 3 b 3 -1 +…+ a n b n -1 ，求T n ．
【单选题】在等比数列{a n }中， a 1 + a 2 +…+ a 5 =27， 1 a 1 + 1 a 2 +…+ 1 a 5 =3 ，则a 3 =（ ）
A.
±9
B.
9
C.
±3
D.
3
【单选题】听力原文： Kraft is one of the world's largest food producers. In America its products include Oreo biscuits and Kool Aid drinks. Like rivals, the company has come under mounting pressure to encourage cons...
A.
Consumers have decreased their purchasing from the Kraft.
B.
Kraft has been being up against to be responsible for its potentially unhealthy foods.
C.
Oreo biscuits produced by Kraft has the food security problems.
D.
Kraft could not make advertisements again.
【简答题】阅读理解 One of the strongest arguments for the raising of the school leaving age(ROSLA)has been that it will bring us some way nearer to'equality of opportunity'. Many people like to think of our present...
【简答题】Food waste in less-developed countries happens mainly at the producers end.
【单选题】China’s New Food Act provides for a food recall system to producers have to stop production their food isn’t up to standards.
A.
that; if
B.
where; if
C.
which; when
D.
when; where
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