问题 单项选择题

体内不产生P450物质的人与产生P450物质的人比较,前者患帕金森氏综合症(一种影响脑部的疾病)的可能性三倍于后者。因为P450物质可保护脑部组织不受有毒化学物质的侵害。因此,有毒化学物质可能导致帕金森氏综合症。
下列哪项,如果为真,将最有力地支持以上论证

A.除了保护脑部不受有毒化学物质的侵害,P450对脑部无其他作用。

B.体内不能产生P450物质的人,也缺乏产生某些其他物质的能力。

C.一些帕金森氏综合症病人有自然产生P450的能力。

D.当用多巴胺——一种脑部自然产生的化学物质治疗帕金森氏综合症病人时,病人的症状减轻。

答案

参考答案:A

解析:这个推理的主线是:(1)P450可以保护脑部组织不受有毒化学物质的侵害,(2)体内产生P450物质的人比较不容易患帕金森氏综合症。所以,有毒化学物质可能导致帕金森氏综合症。要使这个推理成立,就要说明没有别的因素影响推论。
选项A“除了保护脑部不受有毒化学物质的侵害,P450对脑部无其他作用”,就满足这一点。如果没有选项A,比如,除了保护脑部不受有毒化学物质的侵害之外,P450还能够产生一种什么抗原,这种抗原能够使人脑免受帕金森氏综合症之扰的话,题干的推理就不成立了。

阅读理解

Would it surprise you to learn that, like animals, trees communicate with each other and pass on their wealth to the next generation?

UBC Professor Simard explains how trees are much more complex than most of us ever imagined. Although Charles Darwin thought that trees are competing for survival of the fittest, Simard shows just how wrong he was. In fact, the opposite is true: trees survive through their co-operation and support, passing around necessary nutrition "depending on who needs it".

Nitrogen (氮) and carbon are shared through miles of underground fungi (真菌)

networks, making sure that all trees in the forest ecological system give and receive just the right amount to keep them all healthy. This hidden system works in a very similar way to the networks of neurons (神经元) in our brains, and when one tree is destroyed, it affects all.

Simard talks about "mother trees", usually the largest and oldest plants on which all other trees depend. She explains how dying trees pass on the wealth to the next generation, transporting important minerals to young trees so they may continue to grow. When humans cut down "mother trees" with no awareness of these highly complex "tree societies" or the networks on which they feed, we are reducing the chances of survival for the entire forest.

"We didn't take any notice of it" Simard says sadly. "Dying trees move nutrition into the young trees before dying, but we never give them chance." If we could put across the message to the forestry industry, we could make a huge difference towards our environmental protection efforts for the future.

小题1:The underlined sentence "the opposite is true" in Paragraph 2 probably means that trees         

A.compete for survival

B.protect their own wealth

C.depend on each other

D.provide support for dying trees小题2:"Mother trees" are extremely important because they        .

A.look the largest in size in the forest

B.pass on nutrition to young trees

C.seem more likely to be cut down by humans

D.know more about the complex "tree societies"小题3:The underlined word "it" in the last paragraph refers to        .

A.how "tree societies" work

B.how trees grow old

C.how forestry industry develops

D.how young trees survive小题4:What would be the best title for the passage?

A.Old Trees Communicate Like Humans

B.Young Trees Are In Need Of Protection

C.Trees Are More Awesome Than You Think

D.Trees Contribute To Our Society

单项选择题