练习材料：
L42-2: Modern cavemen
The deepest known cave in the world is the Gouffre Berger near Grenoble.
It extends to a depth of 3,723 feet.
This immense chasm has been formed by an underground stream which has tunneled a course through a flawin the rocks.
The entrance to the cave is on aplateau in the Dauphine Alps.
As it is only six feet across, it is barely noticeable.
The cave might never have been discovered had not the entrance been spotted by the distinguished French pot-holer, Berger.
Since its discovery,
it has become a sort of pot-holers'Everest.
Though a number of descents have been made,
much of it still remains to be explored.
A team of pot-holers recently went down the Gouffre Berger.
After entering the narrow gap on the plateau,
they climbed down the steep sides of the cave until they came to a narrow corridor.
They had to edge their way along this,
sometimes wading across shallow streams,
or swimming across deep pools.
Suddenly they came to awaterfall which dropped into an underground lake at the bottom of the cave.
应用配置：L0+L4
知识笔记：extends/ɪkˈstɛndz chasm/kæzəm stream/strim flaw/flɔ plateau/plæˈtoʊ distinguished /dɪˈstɪŋgwɪʃt Everest/ɛvərəst corridor/kɔrədər waterfall/ˈwɔtər
练习感悟：挺长的一大段，初次试了下，勉强在2分钟读完，不断练习，最终完成时间是1分37秒，还行。里面有几个单词发错了，没再调整。