A 16year survey on the arctic Norwegian island of Svalbard found the reindeer (驯鹿) there have declined in weight by an alarming 12 per cent. The reduction in average bodymass is being blamed on global warming.
In research presented lately at a meeting of the British Ecological Society in Liverpool, scientists will explain how rising temperatures are making female reindeer difficult to obtain nutrients during important periods of being pregnant.
Snow in Svalbard typically covers the ground for eight months of the year, which, combined with low temperatures, limits grass growth to June and July. But as summer temperatures have increased by around 1.5℃， grassland has become more productive, allowing female reindeer to gain more weight by the autumn and therefore to conceive (孕育) more calves.
However, warmer winters have brought with them greater rainfall which freezes when it settles on the snow, therefore locking out the reindeer from the lifesupporting food below. As a result, female reindeer are becoming starved, causing them to give birth to much lighter young. The average mass of an adult reindeer in 1998, when the survey began, was 55kg, but by 2016 it had dropped to 48kg.
Professor Steve Albon, an ecologist at the James Hatton Institute in Aberdeen, said that, because the mammals have a relatively high surfaceareatovolume ratio (表面积与体积比), they are no particularly energy efficient.
Reindeer can often access the inadequate food sources beneath the snow by clearing it away with their antlers (鹿角), but they cannot break through the hard ice. Without access to the food in winter, calves are being born far lighter than they should be. Numbers of reindeer have also increased rapidly in the past 20 years, meaning that those which are born are facing greater competition for food. “The implications (含义) are that there may well be more smaller reindeer in the Arctic in the coming decades, but possibly at the risk of catastrophic dieoffs because of increased ice on the ground，” said Professor Albon.
Despite the gloomy findings, reindeer appear to be suffering less from the impact of climate change than some other arctic species.
本文是一篇说明文。研究表明：全球变暖导致驯鹿体重减轻。
1．Which of the following may be the most important reason for the smaller reindeer?
A．Heavy snow. B．Greater rainfall.
C．Hard ice. D．Global warming.
答案：D
解析：细节理解题。根据第一段第二句话“The reduction in average bodymass is being blamed on global warming.”可知，全球变暖是驯鹿平均体重减轻的罪魁祸首。故选D项。
2．According to the passage, rising temperatures will not lead to ________.
A．grass growing more rapidly in summer
B．more rainfall in the arctic area in winter
C．female reindeer's gaining more weight in winter
D．female reindeer's suffering from hunger in winter
答案：C
解析：细节理解题。根据第三段“But as summer temperatures have increased by around 1.5℃， grassland has become more productive...”可知A正确；根据第四段“However, warmer winters have brought with them greater rainfall which freezes when it settles on the snow, therefore locking out the reindeer from the lifesupporting food below.”可知B正确；根据第四段“As a result, female reindeer are becoming starved, causing them to give birth to much lighter young.”可知D正确。根据第四段“The average mass of an adult reindeer in 1998, when the survey began, was 55kg, but by 2016 it had dropped to 48kg.”可知C符合题意。
3．What does the underlined word “gloomy” in the last paragraph mean?
A．Exciting. B．Optimistic.
C．Disappointing. D．Doubtful.
答案：C
解析：词义猜测题。根据最后一段“...reindeer appear to be suffering less from the impact of climate change than some other arctic species.”可知，驯鹿受气候变化的影响似乎比其他北极物种要小。据此推断“Despite the gloomy findings”意为“尽管这一研究发现很悲观”。故选C项。
4．How does the writer develop the passage?
A．By analysing the research.
B．By classification of reindeer.
C．By comparing opinions of experts.
D．By telling stories of different species.
答案：A
解析：写作手法题。通读全文可知，文章主要通过分析研究结果来说明全球变暖对驯鹿体重的影响。故选A项。
