Question

Mosquitoes have an extraordinary ability to target humans far away and fly straight to their unprotected skin. Regrettably，mosquitoes can do more than cause an itchy(发痒的）wound. Some mosquitoes spread several serious diseases，including Dengue， yellow fever and  malaria.

Over one million people worldwide die from these diseases each year. New research now shows how mosquitoes choose who to bite.

Mosquitoes need blood to survive. They are attracted to human skin and breath. They smell the carbon dioxide gas，which all mammals breathe out. This gas is the main way for mosquitoes to know that a warm-blooded creature is nearby.

But mosquitoes also use their eyes and sense of touch. Michael Dickinson is a professor at the California Institute of Technology. His research shows how these small insects，with even smaller brains，use three senses to find a blood meal.

Michael Dickinson’s team used plumes—a material that rises into the air of carbon dioxide gas into a wind tunnel. They then used cameras to record the mosquitoes. The insects followed the plume.

Then，the scientists placed dark objects on the lighter  colored floor and walls of the  tunnel. Mr Dickinson said，at first，the mosquitoes showed no interest in the objects at all.

“What was quite striking and quite surprising is that the mosquitoes fly back and forth for hours. These are hungry females and they completely ignore the objects on the floor and wall of the tunnel. But the moment they get a hit of CO2，they change their behavior quite obvi ously and now would become attracted to these little visual blobs (斑点）.”

This suggested to the researchers that a mosquito’s sense of smell is more important in  the search for food. Once mosquitoes catch a smell of a human  or animal，they also follow  visual signals.

1.What do mosquitoes mainly use to find their targets?

A. Sense of smell. B. Sense of touch.

C. Sense of sight. D. Smart brains.

2.The first response of the mosquitoes to the objects in the experiment is     .

A. to fly to the dark ones

B. to catch and stick to them

C. to take no notice of them

D. to attach themselves to them

3.How can we avoid being attacked by mosqu itoes according to the text ?

A. Don’t let them see us.

B. Use dark objects to stop them.

C. Make them fly back and forth for hours.

D. Attract them to objects full of carbon dioxide gas.

4.What can be the best title for the text?

A. How Do Mosquitoes Survive?

B. Why Do Mosquitoes Need Blood?

C. How Do Mosquitoes Choose to Bite You?

D. Why Do Mosquitoes Attack the Human Being?

Answer

1.A

2.C

3.D

4.C

【解析】

试题分析：本文所叙述的这项研究发表在（当代生物学）杂志上，详实地描述了蚊子在飞行中的各个阶段。有朝一日，我们也许会找到应对蚊子叮咬的办法。

1.A细节理解题。根据最后一段第一句This suggested to the researchers that a mosquito’s sense of smell is more important in the search for food. 这向研究人员表明，蚊子的嗅觉在找寻食物时更为重要。故选A。

2.

期初蚊子对物体根本就不感兴趣。故选C。[来期初源:学§科§网]

3.D推理判断题。根据第二段的第一、二、三句Mosquitoes need blood to survive. They are attracted to human skin and breath. They smell the carbon dioxide gas，which all mammals breathe out. 蚊子依靠血液存活。人类的皮肤和呼吸能够吸引蚊子。它们能够闻到二氧化碳的味道，而一切哺乳动物都会呼出二氧化碳。蚊子依靠血液存活。人类的皮肤和呼吸能够吸引蚊子。它们能够闻到二氧化碳的味道，而一切哺乳动物都会呼出二氧化碳。故选D。

4.

【名师点睛】

抓住文章主线和关键词语，归纳文章中心

要注意不是所有的段落都有主题句，有时主题句暗含在句中。阅读这样的文章，就需要自己根据文章的细节来分析，概括出段落的主题，从而推导出文章的主旨。分析的方法是：先弄清该段落主要讲了哪几方面的内容，这些内容在逻辑上有什么联系，然后加以归纳形成主题。比如第35小题，主旨大意题。根据文章第一段第一句Mosquitoes have an extraordinary ability to target humans far away and fly straight to their unprotected skin. 蚊子具有惊人的能力，可以从远处瞄准目标人群，直接叮向人们裸露的肌肤。

考点：考查科技类阅读