16．Sandstorms hit northwest China's Gansu Province and north China's Inner Mongolia Autonomous Region（内蒙古自治区）on the first day of the new century．According to Sun Landong，a meteorologist （气象学家）with the Lanzhou Meteorology Observatory，visibility（能见度） was less than 100meters in Minqin，a Gansu county near Inner Mongolia，because of sand．When visibility drops to less than 1kilometer，it is called a sandstorm．The sandstorm in Minqin blew up dust in neighboring towns，such as Baiyin，Wuwei，Jinchang and Lanzhou，the capital city of Gansu Province．Dustladen winds also swept into Beijing．Brought by northwesterly blowing at more than 20meters per second，dust first reached the capital's suburbs at 7a．m．，downtown areas at 9a．m..The winds，which died down during the night，brought the temperature down to as low as 8°C below zero and many flights put off their planned time from the city's airport．
It is quite rare for sandstorms，which are frequent between March and June，to happen in winter，when the earth is frozen．The sandstorms in Gansu and Inner Mongolia do not necessarily mean there will be more of them in the spring than last year，when they were serious，but Beijing is taking it very seriously．It is reported that Beijing will spend 6billion yuan（725million dollars）in preventing sandstorms in the capital and has already set up a special team to make sure what causes them．
44．What is the main idea of the passage？B
A．Sandstorms took place in Gansu．
B．Sandstorms happened on the first day of the new century．
C．Sandstorms are very serious，compared with last year．
D．The experts are trying their best to determine the causes of the sandstorms formed this year．
45．Why did sandstorms begin in the winter this year？D
A．Because there was little snow this winter．
B．Because a lot of trees have been cut down．
C．Because people took few measures to control them．
D．It is not mentioned in the passage．
46．Which of the following does NOT belong to the bad effect the sandstorms have done in Beijing？D
A．The temperature fell．B．Flights put off their time to take off．
C．The air was dirty．D．People had three days off．
47．The author wrote the passage toC．
A．tell us the environment is becoming worse and worse
B．explain what measures people have taken to control sandstorms
C．make people realize the need to protect the environment
D．call on us to do what we can to save the earth．
分析 本文主要讲述了在新世纪的第一天，沙尘暴袭击了甘肃省西北部和中国北部的内蒙古自治区，以及对其情况的介绍．
解答 44．B 主旨大意题． 根据文章主题段第一段内容Sandstorms hit northwest China's Gansu Province and north China's Inner Mongolia Autonomous Region（内蒙古自治区）on the first day of the new century主要讲述了在新世纪的第一天，沙尘暴袭击了甘肃省西北部和中国北部的内蒙古自治区，以及对其情况的介绍．结合选项，故B为正确选项．
45．D 细节理解题．根据文章内容It is quite rare for sandstorms，which are frequent between March and June，to happen in winter，when the earth is frozen．可知，通常出现在3月到6月的沙尘暴出现在了天气极冷的冬天是很罕见的，但气象学家并未给出解释为何该现象会发生，故正确答案为D．本文未提及原因．
46．D 细节理解题．根据文章内容dust first reached the capital's suburbs at 7a．m．，downtown areas at 9a．m..The winds，which died down during the night，brought the temperature down to as low as 8°C below zero and many flights put off their planned time from the city's airport．此次沙尘暴带来了大范围的降温，由于能见度减低，很多航班被迫停飞．没有提到人们放假，故选D．
47．C 推理判断题．文章讲述了沙尘暴给甘肃，内蒙以及邻近城市带来的破坏以及不便，而沙尘暴的发生有很大一部分原因是由于人们对环境的破坏，因此作者的目的在于让人们意识到保护环境的重要性，故选C．
点评 本文是人文地理类阅读理解．做这类题材阅读理解时要求考生对文章通读一遍，做题时结合原文和题目有针对性的找出相关语句进行仔细分析，结合选项选出正确答案．推理判断题也是要在抓住关键句子的基础上合理的分析才能得出正确答案，切忌胡乱猜测，一定要做到有理有据．
