OUR ENVIRONMENT AND HOW WE USE IT 19 



always involve a change in the (13) of the molecules ; all other 



changes are (14) Boiling water is a (15) change, and 



burning a match illustrates a (16) change. 



STORY TEST 



MARY TELLS How WE USE THE ENVIRONMENT 



Read carefully and critically. List all the errors and suggest 

 corrections. 



The environment is everything around us. It may be natural 

 or artificial. The factors of the artificial environment are air, 

 light, water, temperature, and something to rest on, or grow from, 

 such as rocks, soil, or the ocean. I have a little garden where I 

 put seeds into the dry earth and the warm sunshine makes the 

 plants develop and grow. It certainly is like magic. Air, water, 

 food, and soil are factors of our environment, but heat, light, and 

 gravity, while we make use of them on occasion, are not really 

 factors of the environment because they are not substances. 

 They are mere creations of the imagination. Fish can live with- 

 out light. We do not need to burn coal to get heat, we can move 

 south where we shall not need it, and gravity is harmful as well 

 as beneficial. It is gravity that makes the disastrous land-slides 

 and causes us to fall down. 



THE REVIEW SUMMARY 



You have now come to the point where you want to find out 

 how much you really understand of the unit you have just studied. 

 To do this best you should be prepared to get up before the other 

 members of your class and, with a brief outline of the unit in your 

 hand, explain to the class any or all of the problems, as your 

 teacher may wish. Perhaps you will be asked to make a recitation 

 on only a single brief topic, or you may be asked to discuss an entire 

 problem. In any event, you will want to prepare an outline from 

 which to recite so that you will not miss any important parts of 

 the unit. In this first unit a suggested outline will be given ; but 

 in the later units you must make your own outline. If you wish 

 to change them, you may do so. These outlines should be based 

 upon what you have read, learned, and done, and upon the big 



