III閱讀測驗:
        Even wondered what it feels like to wake up on Mars? Residents of Sydney and other parts of eastern Australia may have thought they were suddenly on the Red Planet one morning in September 2009. A huge dust storm had descended on the region overnight, covering everything with red soil particles, and all that was visible of the sky was an eerie red glow. What was worse, the choking dust caused hundreds of people to fall ill. Luckily, the storm, which caused Australia’s worse air pollution in seven years, lasted only a couple of days. The red dust had been blown eastward by the wind from the interior of the continent, which has long suffered from drought. Soil in the area is so dry that strong winds were able to lift large amounts into the air and carry it more than a thousand kilometers.
       Although we usually associate dust storms with huge deserts like the Sahara, certain conditions are causing them to appear frequently—and unexpectedly—in areas far from their origin. Australian cities are by no means the only places to have been hit recently. In 2009 alone, major storms occurred in northern China, the western U. S., Africa, and the Middle East. In 2007, dust from China’s Taklimakan Desert was carried far and wide, with Taiwan one of the places worst affected. The rising number of dust storms could be a result of global warming and deforestation. Loss of vegetation causes soil to lose moisture, and a reduction in rainfall due to climate change worsens the problem.
       A serious threat to health, dust storms are regarded as increasingly responsible for respiratory diseases. They may even aid the transmission of airborne infections like influenza and SARS. In the Caribbean, an increase of asthma among children has been linked to dust blown across the Atlantic from Africa. And in California, a serious disease known as “valley fever,” which is caused by a fungus in the local soil, spreads more rapidly in the wake of a dust storm.
      It may sound strange, but not all the effects of dust storms are negative. In fact, these storms may even slow down global warming by reflecting the sun's rays in the atmosphere and increase nutrients in the oceans. Iron-rich dust blown from deserts feeds tiny sea creatures that can absorb large amounts of carbon dioxide. In addition, the South American rainforests are believed to derive many nutrients form dust that is carried from the Sahara. You may not appreciate these benefits, however, if you live in a city that is choking on uninvited red dust.
【題組】66. What does the passage say about Sydney?
(A) People think it looks like the surface of Mars.
(B) Many of the buildings there are painted red.
(C) It is the most polluted city in eastern Australia.
(D) It was covered in red dust one September day.