In fall and winyer many trees lose their leaves in response to cooler temperatures and A. a decrease in average
B. fewer hours of daylight
C. an increase in humidity
D. more direct sunlight ​

im not exactly sure but i think its b!

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.