(A) Decreases: The surface tension of a liquid is inversely proportional to temperature.
$(b)$ Increases; decreases: Viscosity of gases increases with temperature due to increased molecular collisions,while viscosity of liquids decreases with temperature due to decreased cohesive forces.
$(c)$ Shear strain; rate of shear strain: For solids,the shearing force is proportional to shear strain (Hooke's Law),whereas for fluids,it is proportional to the rate of shear strain (Newton's Law of Viscosity).
$(d)$ Conservation of mass: The increase in flow speed at a constriction is primarily a consequence of the continuity equation,which is based on the conservation of mass.
$(e)$ Greater: For a model in a wind tunnel,the characteristic length is smaller,so to maintain the same Reynolds number as the actual plane,the flow speed must be greater.