REVIEW QUESTIONS 149 



Give some examples of each kind, and tell the use of 

 each kind, 



10. Explain how water can be kept in the soil. 

 What is meant by 'dry farming"? Is the farm dry? 



Thus far in our science work we have been learning 

 about the necessities of life: now we shall study some of 

 the things which help to furnish the comforts and con- 

 of civilization. 



