one way to predict the effects of global climates change on an ecosystem is to extrapolate current trends in global change factors into the future. A__of this method is that its predictions __actual observations,but the method also makes the questionable assumptions that the future will,resemble the present.
这个题第一空为什么填virtue呀 从哪里可以看出来呀 第二空填derive from. 求大神指导::>_<::