[求助]GWD30-38的答案是什么？

Q38:

The ancient Nubians inhabited an area in which typhus occurred, yet surprisingly few of their skeletons show the usual evidence of this disease.  The skeletons do show deposits of tetracycline, an antibiotic produced by a bacterium common in Nubian soil.  This bacterium can flourish on the dried grain used for making two staples of the Nubian diet, beer and bread.  Thus, tetracycline in their food probably explains the low incidence of typhus among ancient Nubians.

Which of the following is an assumption on which the argument relies?

1. The tetracycline deposits did not form after the bodies were buried.
2. The diseases other than typhus to which the ancient Nubians were exposed would not be affected by tetracycline.
3. Typhus is generally fatal.
4. Nubian grain became contaminated with tetracycline-producing bacteria prior to being harvested.
5. Bread and beer were the only foods eaten by the ancient Nubians which could have contained tetracycline.

不知道答案是什么？

大家帮忙回答一下吧，谢谢

我下载的GWD的答案是Ａ，但不是很明白，顶起来，求解．

The ancient Nubians inhabited an area in which typhus occurred, yet surprisingly few of their skeletons show the usual evidence of this disease.  The skeletons do show deposits of tetracycline, an antibiotic produced by a bacterium common in Nubian soil.  This bacterium can flourish on the dried grain used for making two staples of the Nubian diet, beer and bread.  Thus, tetracycline in their food probably explains the low incidence of typhus among ancient Nubians.

Which of the following is an assumption on which the argument relies?

A.        The tetracycline deposits did not form after the bodies were buried.

B.        The diseases other than typhus to which the ancient Nubians were exposed would not be affected by tetracycline.

C.        Typhus is generally fatal.

D.       Nubian grain became contaminated with tetracycline-producing bacteria prior to being harvested.

E.        Bread and beer were the only foods eaten by the ancient Nubians which could have contained tetracycline.

B(other than typhus)C(fatal)E(only food)无关

A取非è tetracycline deposits form after the bodies were buried

D取非è
            Nubian grain did not become contaminated with tetracycline-producing bacteria prior to being harvested

我觉得D合理，A不就是已经出现在文中了--- The skeletons do show deposits of tetracycline

Pls help!!

A是对的.A说的是那个deposits 不是后来生成的.如果是后来产生的话,文章说的推理不对了.

D说的东东已经在文章里说了.

This bacterium can flourish on the dried grain used for making two staples of the Nubian diet, beer and bread.

1. The tetracycline deposits did not form after the bodies were buried.
     
2. The diseases other than typhus to which the ancient Nubians were exposed would not be affected by tetracycline.
     
3. Typhus is generally fatal.
     
4. Nubian grain became contaminated with tetracycline-producing bacteria prior to being harvested.

Thank u so much!!

I got it!!

古人没得T病，今人发现其埋葬地遗留有某种抗生素的痕迹。古人常吃的谷物里（古人用这种谷物酿酒、做面包），富含这种抗生素。因此，食物里的这种抗生素帮助古人少得T病。问假设；

A：The tetracycline deposits did not form after the bodies were buried.

抗生素的遗留物不是古人死后才弄来的；

对A取非（削弱了原结论）：

抗生素的遗留物是古人死后才弄来的；

当然是A。这题的前提是tetracycline是typhus的抗生素，因果关系是：因为tetracycline在N人的尸骨中出现，所以N人较低的typhus发病率要归功于tetracycline这玩意在N人的主要食物中出现。

A就是证明“因”有意义