What converts nitrogen into a usable substance during the nitrogen cycle?
A.consumers
B.legumes
C.decomposers
D.nitrogen-fixing bacteria

The movement of water from the atmosphere to the ground is called __________.
A.evaporation
B.precipitation
C.transpiration
D.condensation

Helium in the sun is produced by the following process
A.Nuclear fission
B.Chemical reacttion
C.Nuclear fusion
D.Change of hydrogen from liquid to gas

During which lunar phase may a solar eclipse occur?
A.new moon
B.first quarter moon
C.full moon
D.third quarter moon

Electromagnetic energy can be defined as which of the following?
A.energy that moves as a wave at the speed of light
B.the waves of the electromagnetic spectrum
C.energy that moves as particles at the speed of light
D.the frequency of the emission spectrum