题目

 Birds enjoy a relatively slow rate of extinction but a new study suggests that rate might be severely underestimated(低估). Even worse, if human actions continue, bird extinction rates couldskyrocket and 12 percent of the known bird species(物种) could be dying out by the end of the century. Presently there are 10,000 known bird species — most identified after 1850 — and an estimated 130 of those have become extinct since 1500, setting the extinction rate at about one species every four years. But according to Stuart Pimm of Duke University, this rate fails to take into accoun某长方形足球场周长为350m，长和宽的比为3：2，则长为105105m．国际比赛的足球场的长可以是在100m到110m之间，宽在64m到75m之间，则这个足球场是是可以作国际足球比赛场．（填“是”或“否”）