The problem is that competition ordinarily cannot be observed directly but must be inferred from the spread or increase of one species and the concurrent reduction or disappearance of another species.
问题是，人们通常不能直接观察竞争，而必须从一个物种的扩展或增加和同时另一个物种的减少或消失来推断。
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Last year, Laura, Aaron and Vicky put their heads together for Technovation Kids(TK), an international competition that encourages teenagers to create an app that solves a community problem.
Although some business people are content that the Mexican economy is dominated by a small, powerful clique, many feel that the lack of competition is a serious problem.