题目

阅读理解Published in 1859, Charles Darwin's On the Origin of Speciesmade a number of brave claims about the nature of evolution — including thesuggestion that an animal species with greater diversity in its line will producemore subspecies too. This assumption is not as obvious as you might think atfirst. And it was finally found to be true for birds only a couple of yearsago. Now, researchers from the University of Cambridge in the UK have shownthat Darwin was right on this point for mammals (哺乳动物), too.Apart from being an important contribution to our understandingof evolution 洛江区马甲镇乌潭水库是洛江目前最大的淡水湖，下列关于乌潭水库的描述中属于生态系统的是（　　）A. 乌潭水库中的水 B. 乌潭水库中的水草 C. 乌潭水库中的全部鱼 D. 乌潭水库