[解析]
(1)细节理解题。根据文章第一段Bumblebee (大黄蜂) populations have declined (下降) by 90 percent in the past 20 years.The decline of the bumblebees is highly concerning as they are significant for ecosystems. (大黄蜂的数量在过去的20年里下降了90%。大黄蜂的减少是高度关注的,因为它们对生态系统具有重要意义。)可知,大黄蜂的数量在过去的二十年里大幅度减少。故选B。
(2)细节理解题。根据文章第三段Kevan and his colleagues decided to take a closer look at the facts relating to bumblebee populations across the world.Kevan and the colleagues looked at 180 years of literature on the species and found one common reason across all bumblebee species that they can survive in temperatures up to 36 degrees Celsius,but the perfect temperature for nests is between 28 to 32 degrees Celsius.(Kevan和他的同事们决定仔细研究一下与世界各地大黄蜂种群有关的事实。Kevan和他的同事们查阅了180年来关于这个物种的文献,发现了所有大黄蜂物种都能在36摄氏度的温度下生存的一个共同原因,但筑巢的最佳温度是28到32摄氏度。)可知,Kevan和他的同事们是通过研究关于大黄蜂的文献来进行研究的。故选D。
(3)观点态度题。根据文章最后一段Although the studies led by Kevan have limitations,the potential effects for bumblebee health and conversation are large and long﹣term.(虽然Kevan的研究存在局限性,但对大黄蜂健康和交流的潜在影响是巨大而长期的。)可知,作者对Kevan的研究持支持态度。故选B。
(4)标题归纳题。根据文章第二段And now,a new study published in the Frontiers in Bee Science has found that the rising heat caused by global warming might be a reason for the decrease in numbers across the globe. "The decline in populations and ranges of several species of bumblebees may be explained by issues of overheating of the nests," Peter Kevan of the University of Guelph in Canada and lead author of the study said in a statement.(现在,发表在《蜜蜂科学前沿》上的一项新研究发现,全球变暖导致的气温上升可能是全球蜜蜂数量减少的一个原因。加拿大圭尔夫大学的Peter Kevan是这项研究的主要作者,他在一份声明中说:"一些大黄蜂物种的数量和范围的下降可能是由于巢穴过热的问题造成的。")以及全文内容可知,文章主要围绕大黄蜂种群数量下降的问题展开,通过引用研究数据、专家观点等,解释了这一现象可能的原因﹣﹣﹣全球变暖导致的温度升高。D选项Research Shows the Main Reason of Bumblebee Decline(研究揭示了大黄蜂数量下降的主要原因)是最合适的标题。故选D。