GWD 28，我的答案，大家来交流一下！

iaasip

以下是引用xuedidage在2005-12-9 8:34:00的发言：

28-28: Which of the following most logically completes the argument?

A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.

A: histidine is found in all parts of the plant – roots, stem, leaves, and flowers

B: the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids

C: others of the closely related group of plants are also found to produce histidine in large quantities

D: cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic

E: the concentration of histidine in the growing herb declines as the plant approaches maturity

I strongly recommend D for answer.  Only D supports that the amino acid makes the soil's mineral inert.  

agree

pls discuss

iaasip

28-30: Unlike the body’s inflammatory response to cuts and sprains, with widespread swelling and stiffness immobilizing the injured area until it heals, the body’s response to sunburn is more localized and resulting in a distinct line dividing affected and unaffected areas of the skin.

A: with widespread swelling and stiffness immobilizing the injured area until it heals, the body’s response to sunburn is more localized and resulting

B: where the injured area is immobilized with widespread swelling and stiffness until it has healed, sunburn generates a more localized response in the body, which results instead

C: with the injured area immobilized by means of widespread swelling and stiffness until healing, sunburn generates a more localized response in the body, one resulting

D: in which widespread swelling and stiffness immobilize the injured area until it has healed, the body’s more localized response to sunburn results

E: in which widespread swelling and stiffness immobilize the injured area until healing, instead, the body’s more localized response to sunburn results

I choose E

who can explain why E is wrong and what dose "it" in D refer to

thanks

sunnybright

以下是引用tonywzj在2005-11-22 0:56:00的发言：

gwd 28-28

28-28: Which of the following most logically completes the argument?

A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.

A: histidine is found in all parts of the plant – roots, stem, leaves, and flowers

B: the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids

C: others of the closely related group of plants are also found to produce histidine in large quantities

D: cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic

E: the concentration of histidine in the growing herb declines as the plant approaches maturity

这题好像什么答案都有，除了B没人选。

我认为是D，请注意histidine...renders these metals chemically inert. 这句话的意思是氨基酸使得金属的变得惰性，我理解为使得金属的毒性不再挥发出来了。那如果种herb种一段时间，连别的怕这种金属毒性的植物都可以种了，那不正是支持了结论：the herb’s high histidine production is what allows it to grow in metal-rich soils（原因是histidine抑止了金属毒性）

我认为是C, 因为种植物有histidine，而这种植物和others of the closely related group of plants 可以thrive in soil with metals，如果发现其他植物也有histidine, 那就可能使这一共性让它们能thrive in soil with metals.

D不对， 说一段时间后能改变土壤，但并不能说明原因是histidine, 也许是植物的其他特性导致的。

sunnybright

28-29: Lofgren’s disease has been observed frequently in commercially raised cattle but very rarely in chickens.  Both cattle and chickens raised for meat are often fed the type of feed that transmits the virus that causes the disease. Animals infected with the virus take more than a year to develop symptoms of Lofgren’s disease, however, and chickens commercially raised for meat, unlike cattle, are generally brought to market during their first year of life.

Which of the following is most strongly supported by the information provided?

A: The virus that causes Lofgren’s disease cannot be transmitted to human beings by chickens.

B: There is no way to determine whether a chicken is infected with the Lofgren’s disease virus before the chicken shows symptoms of the disease.

C: A failure to observe Lofgren’s disease in commercial chicken populations is not good evidence that chickens are immune to the virus that causes this disease.

D: An animal that has been infected with the virus that causes Lofgren’s disease but that has not developed symptoms cannot transmit the disease to an uninfected animal of the same species.

E: The feed that chickens and cattle are fed is probably not the only source of the virus that causes Lofgren’s disease.

答案是C,我选B. 因为的了病，只有超过一年才看出来，鸡不到一年就卖了，就是得了病，也看不出来。

而C中"immune"文中没有牵涉到，所以推不出来。

wooder_whj

gwd 28-28

28-28: Which of the following most logically completes the argument?

A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.

A: histidine is found in all parts of the plant – roots, stem, leaves, and flowers

B: the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids

C: others of the closely related group of plants are also found to produce histidine in large quantities

D: cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic

E: the concentration of histidine in the growing herb declines as the plant approaches maturity

以下是引用sunnybright在2006-1-8 2:22:00的发言：

我认为是C, 因为种植物有histidine，而这种植物和others of the closely related group of plants 可以thrive in soil with metals，如果发现其他植物也有histidine, 那就可能使这一共性让它们能thrive in soil with metals.

D不对， 说一段时间后能改变土壤，但并不能说明原因是histidine, 也许是植物的其他特性导致的。

我同意sunnybright对 D选项的分析 ，但我认为答案是E.

因为histidine in test-tue solutions 中能和metals 发生化学反应renders these metals chemically inert.如果histidine 在真实的环境中也确实和metals发生了化学反应，那么就可以Support that the herb’s high histidine production is what allows it to grow in metal-rich soils.正如选项E the concentration of histidine in the growing herb declines as the plant approaches maturity,按理the concentration of histidine producted by the plant 如果没有和其他物质发生化学反应的话，随着时间的增长，histidine  的浓度应该会越积越多，已知histidine  能和metals发生化学反应,而现在the concentration of histidine 也降低了，因此，可以断定在现实的环境中histidine确实renders these metals chemically inert.

sunjie38

正确答案为:

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