听力原文

On the border between India and Tibet the rocks have been raised eight kilometres above sea level, creating the world's highest mountain range, the Himalayas.
印度与西藏的交界处，巨大的岩石被推挤至海平面以上8000米处之高，造就了世界最高大宏伟的山脉 ——喜马拉雅山。
But to the east, the rocks have buckled into a series of steep north-south ridges, cutting down through the heart of Yunnan, the parallel mountains of the Hengduan Shan.
对东部来说，岩石被皱褶进了南北走向的绵延陡峭的山脊，同时也切进了云南的心脏地带，形成了平行的横断山脉。
These natural barriers serve to isolate Yunnan's plants and animals in each adjacent valley.
这些天然屏障守护着隔绝在云南，各自毗邻的河谷中的动植物。
While the huge temperature range between the snowy peaks and the warmer slopes below provides a vast array of conditions for life to thrive.
雪峰与斜坡间的巨大的温差，所创造的足够的优厚条件，使得这儿生命彰显无限生机。
Through spring, the Hengduan slopes stage one of China's greatest natural spectacles. The forests here are among the most diverse botanical areas in the world.
春的岁月，横断山脉的斜坡上上演了中国最为壮绝的自然景致。此处的森林拥有世界上最多样化的植被及物种。
Over 18,000 plant species grow here, of which 3,000 are found nowhere else.
这里生长着超过18000种植物，其中约3000种植物是这儿特有的。

重点讲解

重点讲解：
1. a series of
一连串；一系列；连续；接连；
eg. A series of mischance happened.
一连串不幸的事发生了。
eg. The student always asks his teacher a series of questions.
这个学生总是问他老师一连串的问题。
2. serve to do
用作；充作；
eg. Their brief visit has served to underline the deep differences between the two countries.
他们短暂的访问恰恰凸显了两国间分歧的严重程度。
eg. A single example will serve to illustrate the point.
只举一个例子就可以把问题说清楚了。
3. range between
（在一定幅度内）变化，变动；
eg. Prices range between 7 and 10.
售价在7英镑和10英镑之间。
eg. The temperature ranges between 30 and 40 degrees centigrade.
温度在摄氏三十度与四十度之间。