4. 一个地方的rainforest 被减少了3%(不确定),但是补种的树是4%(肯定比3%大)。所以有人argue rainforest的面积在expanding, 问weaken。 楼主纠结于两个答案,一个是没有考虑补种的树也有被cut的可能性,另外一个忘了。 Well, if all the newly planted trees concentrated on only 1% are of the rain forest, the area of the rain forest is not expanding. Or if, on average, a newly planted trees can only cover half of the "area" which was covered by a mature tree. -- by 会员 sdcar2010 (2011/8/31 9:50:42)
Thanks for your analysis, and it reminds me of another choice which says that there is certain percentage of old-grown trees in the existing rainforest. I guess this one should be the right choice. |