2 Written Questions

1. __________is the process in which bacteria and fungi break down a dead organism's tissues and use some of the carbon as food
2. plants make proteins from ____________in the soil

2 Multiple Choice Questions

1. burning fuels in cars and factories upsets the balance of the ___________cycle
   1. carbon-oxygen
   2. nitrates
   3. petroleum
   4. decay
2. cold air causes water vapor to __________and form _________
   1. decay
   2. carbon-oxygen
   3. condense, clouds
   4. petroleum

1 True/False Question

1. petroleum → _________is made from decayed organisms

   True        False