When irrigating, enough water should be applied to wet the soil to what depth?

When irrigating, enough water should be applied to wet the soil to what depth?
 
  a. 6 to 12 inches c. 18 to 20 inches
  b. 12 to 16 inches d. 16 to 18 inches

Question 2

The most popular enrichment material for both recreational and aesthetic enjoyment is what?
 
  a. animal life c. water
  b. plant life d. rolling terrain

Question 3

What type of fern is popular for hanging baskets?
 
  a. Boston c. Baltimore
  b. Chicago d. Denver

Question 4

Radial trenching is a technique used in the irrigation of trees and shrubs.
 
  Indicate whether the statement is true or false