316-318

1. Most of the United states is covered by ___ soil\
5. is the part of the soil that is made of decayed organic materials
7. the minerals are not washed away by ____
8. Most of the US is covered by ____ soil
11. and prairies of the US are found between the Rocky Mountains and the eastern forests
13. because desert areas receive little rain, plants have special ___ to grow there
15. covers the ground in rain forests, grasslands, and deserts

2. most of the forest soil in the US is in the ___ third of the country
3. Most of the US is covered by ____ soil
4. you will find less humus in ____ and lots of fine particles of rock, such as the particles that make up clay.
5. Each layer of soil is called a soil ____.
6. soil can be ___ by flowing water and wind
9. most plant roots grow in the ____.
10. having to do with or coming from living things
12. mixture of bits of rock and bits of once-living parts of plants and animals
14. humus contains ____ that feed plants