(a) When wet clothes are spread on a stand the water evaporates and the surrounding air tends to get saturated thus hampering the process of drying . On a windy day when breeze blows the nearby wet air is replaced by dry air which helps the process of evaporation further. Thus clothes dry quicker when there is a bredze.
(b) the explanation is the same as given above. On a humid day the air is already saturated with water vapour. This means that the water that comes out of the pores of the body as sweat does not vaporise. This will result in greater sweating on a humid day.