学术英语理工类第18篇摘要

Whether Marijuana will ultimately harm or benefit human functioning has aroused contradictory opinions.This text empirically estimates the physical effects of marijuana use.The study is divided into two parts---short-term and long-term effects.The first part introduces effects at the beginning of use.The most common sign is a increase of pulse rate and reddening of the eyes.Other biochemical effects such as increased hunger,affected muscle strength are also a significant consideration.Short-term effects can be classified into two groups--enduring ones like nausea,vomiting and less enduring ones like headaches ,exhaustion.According to researches,the physical effects of Cannabis depend upon the experience which an individual has with it.The second part discusses long-term effects when a user is into the situation.Recent experiments performed on long-term “pot”smokers show that body’s production of DNA is interfered greatly.Researchers also founded out that a great majority of marijuana users develop an increase in chromosome breaks significantly.Furthermore,men smoking too often have a lower level of male sex hormone than nonsmokers,which lowers sperm counts.Owing to all kinds of elements such as sanitation, climate ,drug dose level,it would be easier for marijuana to cause disorders which aren’t attributed to it .All in all,the text concludes that there are still much to be learned about physical effects of Cannabis.