1
2
3
4
5
100


a person who belongs to the same age group or social group as someone else



Peer


100


someone who was a student at a particular school, college, or university



Alumnus (pl.-i-)


100


also has the potential to change rainfall and snow patterns, increase droughts and severe storms.



Global warming


100


substances discharged into the air (as by a smokestack or an automobile engine)



emissions 


100


are a trendy group of widely discussed ingredients.



Whole grains


200


activities that relate to the buying and selling of goods and services over the Internet;



e-commerce 


200


are countries with little industrial and economic activity where people generally have low incomes.



Developing countries 


200


has been pinned down to one major human activity.



ozone layer depletion



200


of the fields could happen through overuse or misuse of pesticides.



Contamination


200


is another important component of healthy diet. It’s found in cereals, fruits, and vegetables, and contributes to keeping our digestive system healthy.



Fiber


300


the programs that run on a computer and perform certain functions.



software


300


(sometimes sweat factory) is a workplace with unacceptably severe conditions and usually extremely low wages.



Sweatshop 

300


is a power produced by the surge of ocean waters during the rise and fall of tides.



Tidal energy


300


s an area of land that is used to dispose of waste.

 


Landfill.


300


having the appearance or quality of syrup; thick or sweet;



syrupy


400

a device made of a hollow tube and a needle that is used to force fluids into or take fluids out of the body




syringe


400


is the process of implementing and developing technical standards.



standardization


400


rain that contains dangerous chemicals because of smoke from cars and factories;



acid rain 


400


a sudden and terrible event in nature (such as a hurricane, tornado, or flood) that usually results in serious damage and many deaths;



natural disaster


400


having a strong, pleasant, and somewhat spicy flavor;



zesty 


500


a drug that decreases or removes pain that you feel in your body



painkiller


500


a state or condition in which different things do not occur in equal or proper amounts;



imbalance / inequality 


500


The process by which towns and cities are formed and become larger as more and more people begin living and working in central areas;



urbanization


500


a substance (such as manure or a special chemical) that is added to soil to help the growth of plants;



fertilizers


500


it is a slightly less formal expression which means an activity requiring considerable intelligence and ability.



rocket science