雅思阅读辅导：不同生物的寿命差异

　　阅读段落

　　Every organism has a life span which is highly characteristic. There are striking differences in life span between different species, but within one species the parameter is relatively constant. For example, the average duration of human life has hardly changed in thousands of years. Although more and more people attain an advanced age as a result of developments in medical care and better nutrition, the characteristic upper limit for most remains 80 years. A further argument against the simple wear and tear theory is the observation that the time within which organisms age lies between a few days and several thousand years, as with mammoth trees.

　　段落大意

　　本段介绍了不同生物之间寿命的差异，以及同类生物寿命长度的相对稳定性。

　　阅读笔记

　　Life span differs between different species within one species parameter is Relatively constant

　　E.g. human life

　　Argument against the simple theory observation

　　逻辑关系

　　1. 对比

　　More and more people attain an advanced age as a result of developments in medical care and better nutrition.

　　The characteristic upper limit for most remains 80 years.