D. one year
7. which of the following is not a characteristic of topsoil?
a. it develops very slowly and is the most utilized part of soil
b. it makes up the top two to eight inches of soil
c. it is the most fertile part of the land for growing plants
d. it develops very quickly and is the most utilized part of soil

Directions: read the descriptions of the four islands presented in the lesson. 1. list two new traits that each new species of rat might demonstrate as it adapts to the conditions on each island. 2. introduce one of the four new rat species to another island and describe one challenge it would encounter and one success as it adapts to its new environment.