The tropics contain a larger surface area of land than higher latitudes——a fact that is not always evident when we examine commonly used projections of Earth's curved surface, since this tends to exaggerate the areas of land in the higher latitudes——and some biogeographers regard the differences in diversity as a reflection of this effect. (TPO40, 55)

　　tropics n. 热带

　　projection n. 发射，投射;

　　exaggerate /?g'zæd??re?t/ v. 夸张，夸大

　　大家自己先读，不回读，看一遍是否能理解

　　The tropics contain a larger surface area of land than higherlatitudes——(a fact) (that is not always evident) (when we examine commonly used projections of Earth's curved surface), (since this tends to exaggerate the areas of land in the higher latitudes)——and some biogeographers regard the differences in diversity as a reflection of this effect. (TPO40,55)

　　托福阅读长难句100句分析：

　　这个句子的主干就是一个并列结构，中间被一个破折号隔开了。

　　The tropics contain a larger surface area of land than higher latitudes and some biogeographers regard the differences in diversity as a reflection of this effect.

　　修饰一：(a fact) ，同位语

　　中文：一个事实

　　修饰二：(that is not always evident) ，从句

　　中文：不总是那么明显

　　修饰三：(when we examine commonly used projections of Earth's curved surface) ，从句

　　中文：当我们在仔细观察通常所用的地球曲面投影时

　　修饰四：(since this tends to exaggerate the areas of land in the higher latitudes) ，从句

　　中文：因为这往往夸大了高纬度的土地面积

　　托福阅读长难句100句参考翻译：

　　热带比高纬度包含更大的的土地面积——当我们在仔细观察通常所用的地球曲面投影时，这一事实并不总是显而易见的，因为这往往夸大了高纬度的土地面积——并且一些生物地理学家认为多样性的差异反映了这一影响。

　　这个句子的主要修饰成分就是从句和同位语，大家务必想清楚，每一个修饰成分修饰的是什么，才能看清楚这个句子的结构。