Which "sphere" is not directly studied in one of the main branches of Earth/space science (geology, astronomy, meteorology, or oceanography)?
a. biosphere
b. exosphere
c. atmosphere
d. hydrosphere
The correct answer is letter A. Biosphere is not directly studied in one of the main branches of Earth/Space science. This is a branch of science that focuses on living organisms that are living in different populations or communities all over Earth. The other three choices directly study these branches of Sciences.
