GRE作文新增的argument题目(2)_GRE写作

GRE作文新增的argument题目(2)

　　although black bears are common in the eastern canadian province of labrador, grizzly bears―often similar in color, but much larger―were believed to exist only in the western provinces. despite a nineteenth-century explorers account of having startled and narrowly escaped from a grizzly bear deep in the woods in labrador, modern scientists find no physical evidence that grizzly bears have ever lived in labrador. but recent research into the language and legends of the innu, a people who have lived in labrador for thousands of years, reveals that their language has words for two different kinds of bears, and their ancient legends attribute different characteristics to the two kinds of bears. therefore, there probably were grizzly bears in labrador, and the explorers account probably accurately identified the bear.

　　scientists studying historical weather patterns have discovered that in the mid-sixth century, earth suddenly became significantly cooler. although few historical records survive from that time, some accounts found both in asia and europe mention a dimming of the sun and extremely cold temperatures. either a huge volcanic eruption or a large meteorite colliding with earth could have created a large dust cloud throughout earths atmosphere that would have been capable of blocking enough sunlight to lower global temperatures significantly. a large meteorite collision, however, would probably create a sudden bright flash of light, and no extant historical records of the time mention such a flash. some surviving asian historical records of the time, however, mention a loud boom that would be consistent with a volcanic eruption. therefore, the cooling was probably caused by a volcanic eruption.