练习材料：

L42-1: Modern cavemen

Cave exploration, or pot-holing, as it has come to be known, is a relatively new sport. Perhaps it is the desire for solitude or the chance of making an unexpected discovery that lures people down to the depths of the earth. It is impossible to give a satisfactory explanation for a pot-holer's motives. For him, caves have the same peculiar fascination which high mountains have for the climber. They arouse instincts which can only be dimly understood.

Exploring really deep caves is not a task for the Sunday afternoon rambler. Such undertakings require the precise planning and foresight of military operations. It can take as long as eight days to rig up rope ladders and to establish supply bases before a descent can be made into a very deep cave. Precautions of this sort are necessary, for it is impossible to foretell the exact nature of the difficulties which will confront the pot- holer.

任务配置：L0+L4

知识笔记：

pot-holing n.洞穴勘探

caveman n.(远古)洞穴人

cave exploration 洞穴勘查

solitude n.独处，独居

lure v.引诱

pot-holer n.洞穴探险者

as it has come to be known 正如已逐渐为人所了解的那样

dimly adv.昏暗地，模糊地

foresight /'forsait/  n.深谋远虑

rambler n.漫步的人

It is the desire...or the chance...that 强调句式，the desire...or the chance...为被强调部分

give an explanation 作出解释

fascination n.吸引力

have a fascination 有吸引力

ladder n.梯子

fortell /for'tel/ v.预言 to say what will happen in the future,especially by using special magical powers

special magical power超凡能力

relatively adv.相对地，比较而言

satisfactory adj.满意的

military /'milətɛri/ 军事的

descent /di'sɛnt/ n.下降

precaution /pri'kɔʃən/ n.预防措施

confront v.遇到

deal-dealt-dealt

undertaking n.任务

arouse v.引起，唤醒

rig up 装配，搭起

for表原因，引导原因状语从句，一般放句中

练习感悟：

Never leave the things until tomorrow you can do today.