TPO-1中“Timberline Vegetation on Mountains”这篇文章最后一题

ynkmttUID: 3241349

请问TPO第一套中“Timberline Vegetation on Mountains”这篇文章最后一题答案是BDF还是BCD，我是先用TPO的软件做，然后在用文勇黄金89篇作分析，结果发现软件提供的答案和文勇89篇的答案不一样。希望有人可以回复下正确答案，谢谢

史殿金UID: 3319267

○There is no agreement among scientists as to exactly why plant growth is sharply different above and below the upper timberline.
○The temperature at the upper timberline is probably more important in preventing tree growth than factors such as the amount of snowfall or the force of winds.
○The geographical location of an upper timberline has an impact on both the types of trees found there and their physical characteristics.
这三个