Question: Q: The nitrogen that enters living systems by nitrogen fixation is successively converted from organic nitrogen back into nitrogen gas by what? Choices: - algae - pollen - viruses - bacteria A:
Answer: bacteria

Question: Q: If an air mass forms over an ocean it is called what type of air mass? Choices: - cumulus - hurricane - tropical - maritime A:
Answer: maritime

Question: Q: Will contour lines ever cross? Choices: - yes - in rare cases - always - no A:
Answer:
no