Concept:Crop spoilage in a storage structure is mainly caused by dampness, which develops from high relative humidity.
Explanation:High relative humidity causes moisture to accumulate on stored crops.
This moisture encourages the growth of mould and decay-causing organisms.
Low temperature can also cause condensation on the surface of the crops.
Condensation adds more moisture, which increases the chances of spoilage.
Therefore, the combination of low temperature and high relative humidity is harmful to stored crops.
Answer:B. Low temperature and high relative humidity
