Question

【題目】閱讀理解。

Contrary to people's previous knowledge, it's food shortage not dietary preference that motivates birds to migrate thousands of miles back and forth between breeding and nonbreeding areas each year, a new research shows.

“It's not whether you eat insects，fruits or candy bars or where you eat them that counts，but how reliable that daytoday food source is，” said the study leader W．Alice Boyle of the University of Arizona.

To figure out the underlying pressure that drives some birds to leave home for the season，Boyle examined 379 related species of New World flycatchers(捕蠅鳥) and compared their sizes，food types, habitats, migratory behaviors and whether or not they fed in flocks.

To compare the birds，the researchers constructed a “supertree” showing the exact evolutionary relationships among different species.

A computer analysis then determined whether a particular species was migratory because it ran in the “family” or whether something in the bird's environment was forcing it to leave each season.Boyle and her colleagues found that food shortage was the number one issue that predicted a species' migratory behavior. “Food availability is the underlying pressure, not diet and habitat，” Boyle said.

An alternative strategy that the birds use to handle food shortage is to hunt in flocks, since a group is more likely to find a new source of food than an individual.

“If you suffer from food shortage, you have two options，” Boyle said.“You can either hunt with other birds or you can migrate.”

【1】Birds were thought to migrate in order to ________.

A．seek their favorite food ina new place

B．a(chǎn)void being constantly hunted

C．breed more young in a new place

D．a(chǎn)djust themselves to the changes of weather

【2】What is Paragraphs 3 and 4 mainly about?

A．The aim of the research.

B．The basis of the research.

C．The process of the research.

D．The findings of the research.

【3】The passage implies that ________.

A．the birds' food sources are getting rare in the world

B．the living surroundings are severe for birds

C．birds search for food separately

D．birds can survive only by hunting in flocks

【4】For what purpose does the author write the text?

A．Educating readers.

B．Informing readers.

C．Drawing people's attention.

D．Condemning the bad environment.

Answer 1

【答案】

【1】A

【2】C

【3】A

【4】B

【解析】

試題分析：

【1】細節(jié)理解題。根據(jù)第一段第一句中“Contrary to people's previous knowledge, it's food shortage not dietary preference that motivates birds to migrate”可知，是食物的短缺而不是對食物的偏好驅(qū)使鳥類遷徙，這一新的研究結(jié)果推翻了人們過去錯誤的觀點，即人們過去認為：是對食物的偏愛驅(qū)使鳥類遷徙。故選A項。

【2】段落大意題。根據(jù)第三段中“examined 379 related species of New World flycatchers(捕蠅鳥)”和“compared their sizes，food types，habitats，migratory...”可知，第三段介紹了采集樣本、對比樣本的過程。根據(jù)第四段中“constructed a ‘supertree’ showing...”可知，第四段介紹了研究方法。由此可知，第三、四兩段綜合說明了此項研究是如何進行的。故選C項。

【3】推理判斷題。根據(jù)文章第一句“...it's food shortage not dietary preference that motivates birds to migrate thousands of miles back and forth...”可知，是食物的短缺而不是對食物的偏好驅(qū)使鳥類遷徙。由此可推知，世界上鳥類的食物資源正在減少。故選A項。

【4】寫作意圖題。文章從第一段提出重大發(fā)現(xiàn)到后面幾段敘述研究過程，再到最后一段的研究結(jié)論可知，本文的寫作目的是告知讀者這一研究的新發(fā)現(xiàn)。故選B項。