What is the likely cause of the blockage in the following scenario? A plumber, cleaning out recently blocked lines, indicates that there are roots blocking the sewer system. There are no trees immediately over the sewer line and have not been for years, there is only a small group of trees on the side of the property, several yards from the line.
A. taproots
B. aerial roots
C. lateral roots
D. primary roots

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.

most community's take hundreds of years to become stable

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

food source and hunting?