Earth's six principal subsystems are ____________________, ...

[ereecah]

Earth's six principal subsystems are ___________________ _, ___________________ _,
  ___________________ _, ___________________ _, ___________________ _, and
  ___________________ _. Fill in the blank(s) with the appropriate word(s).

Question 2

Physical geology is the study of ___________________ _. Fill in the blank(s) with the appropriate word(s).

[joshraies]

Answer to Question 1

atmosphere, hydrosphere, biosphere, lithosphere, mantle, core

Answer to Question 2

Earth materials, such as rocks and minerals, as well as the processes operating within Earth and on its
surface