7. when two or more species live together in a close, long-term relationship, it is called

8. a symbiotic relationship in which both participating species benefit is called

9. a symbiotic relationship in which one species is neither harmed nor called

significant amounts of nitrogen oxides, carbon monoxide, and other pollution

explanation:

passenger vehicles are a major pollution contributor, producing significant amounts of nitrogen oxides, carbon monoxide, and other pollution. in 2013, transportation contributed more than half of the carbon monoxide and nitrogen oxides, and almost a quarter of the hydrocarbons emitted into our air.

answer; /// i believe the correct answer is (thrombocytopenia); (a)