4．By 2050，half of the world's population will live in the tropics-the relatively warm belt that circles the globe-according to State of the Tropics，a report released today．Rapid population growth，along with economic growth，means that the region's influence will grow in coming decades，the authors of the 500-page work predict．
The project，first launched in 2011，aimed to answer one significant question：Is life in the tropics improving？To find out，the researchers analyzed environmental，social，and economic indicators collected over 6decades．It finds that the region has made"extraordinary progress"in many areas．For example，more people have access to safe drinking water，and the number of protected areas is increasing．The tropics also have outperformed the rest of the world in economic growth over the past 30years．
However，some challenges remain．Investment in research and development，for example，has increased cautiously，but tropical nations still invest less than the rest of the world．"As a proportion of GDP the Rest of the World invests almost four times as much in research and development than the Tropics．"concludes the report．
The report also includes a new analysis of how climate change will affect the region．Many plant and animal species are moving poleward in an attempt to stay within their preferred environmental conditions in the tropics，the authors write．However，some organisms may not be able to keep pace with the changing conditions，they predict．As a result，they can experience population declines or go extinct．
In addition，an expanded tropical zone also threatens health and safety issues，the authors warn．As regions become more suitable to insects such as mosquitoes and ticks，the spread of insect-borne diseases such as malaria，dengue，and Lyme disease could rise，causing a burden to human health and the economy．
Bruna，a researcher，says he sees a lot to be concerned about in the report．"While we've made incredible advances in some areas，I think the risks for the tropics that are highlighted in this report are things that we really need to be concerned about．"
47．What was the original purpose of the project State of the TropicsA？
A．To answer if life in the tropics is improving．
B．To do research about environment，society and economy．
C．To warn people of the problems in coming decades．
D．To help the development in the tropics．
48．What can we learn from the passageB？
A．Economic development in tropics has increased less over the past 30years．
B．Some organisms can experience population drop or extinction for climate changes．
C．Rapid population growth contributes to the outbreak of infectious diseases．
D．Great investment has been adopted in the research and development．
49．According to the passage，we can inferA．
A．close attention needs to be paid to the risks for the tropics．
B．all the plants and animals will live in the polar region in the future．
C．health and safety problems will influence the tropical development．
D．Bruna shows positive attitude towards the future of the tropics．
50．Which of the following best describes the writer's attitudeC？
A．Critical．
B．Optimistic．
C．Objective．
D．Subjective．
分析 本篇文章是一篇政治经济类的短文阅读．文章指出，到21世纪50年代，世界上将有一半左右的人生活在热带区域带．并且主要针对热带区域的现状以及经济的发展等问题展开了论述，分析其利弊，呼吁大家多加关注这一地区的发展，政策和资金的投入上等都应该多向这些地区倾斜一些．
解答 47-50ABAC
47．A．细节理解题．根据第二段一句The project，first launched in 2011，aimed to answer one significant question：Is life in the tropics improving？可知，这个项目的最初目的是回答热带地区生活是否能得到改善这一问题的；故选A．
48．B．细节理解题．根据第二段The tropics also have outperformed the rest of the world in economic growth over the past 30years．可知，热带地区的经济水平在过去的三十年里是有了很大的提高的，所以A项错误；第四段最后一句As a result，they can experience population declines or go extinct．可知，B项的描述是正确的；由第五段the spread of insect-borne diseases such as malaria，dengue，and Lyme disease could rise，causing a burden to human health and the economy．可知，害虫的蔓延才是当地传染病发生的罪魁祸首，可排除C；由第三段第二句话的后半部分but tropical nations still invest less than the rest of the world可知，对当地的投资是偏少的，所以D项错误；故选B．
49．A．推理判断题．根据最后一段Bruna，a researcher，says he sees a lot to be concerned about in the report以及引用的Bruna的话可推知，这一地区的发展还是需要更多人关注的；故选A．
50．C．作者观点题．通篇文章的描述都是以一种客观的语言来论述的，没有加自己的个人观点和评论，由此可知，作者的态度应该是客观的；故选C．
点评 本文为政治经济类阅读文章，该类文章时代气息浓郁，语言鲜活，但熟字新义词、超纲词及专业词语多，长句、难句多．政治类文章大多数是同学们感性趣的内容，读起来倒有似曾相识的感觉，阅读这类文章，要抓住文章的核心，即文章整体和各段主要在说什么，也要注意段落之间的逻辑关系
