Give one example of SECONDARY succession:

Fire

Explanation:

Fire is one of the most common causes of secondary succession and is an important component for the renewal and vitality of many types of ecosystem. Fires may either take place naturally, for example when lightning strikes a dry habitat, or may involve controlled, systematic burning of a landscape by humans.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.