Answer:

(a) A body with high reflectivity absorbs heat radiation poorly. Poor absorbers emit poor radiations. So a reflective body is a poor emitter.

(b) Brass conducts heat well while wood does not. Whenever we touch a brass tumbler, we lose heat from our hands to the tumbler. So we’re cold. On a cold day, the hand transfers very little heat to the wooden tray, and the body temperature does not drop considerably. So we are not cold.