three emission line involving three energy levels in an atom occur at wavelength x,1.5 x, and 3.0x nm which wavelength corresponds to the transition from the highest to the lowest of the three energy levels​

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.

Combustion is the act or process of burning. therefore, i believe the answer is  a: burning wood.