A) feeding the nestmates
B) feeding the brood
C) cleaning the cells
D) packing the pollen

A) because instinctive behaviours are incomplete the first few times they are displayed, while learned behaviours are apparently a product of reason
B) because instinctive behaviours are dependent upon experience, while learned behaviours are genetically programmed responses
C) because instinctive behaviours are acquired from observation, while learned behaviours are acquired from practice
D) because instinctive behaviours are genetically programmed responses, while learned behaviours are dependent upon experience

A) They produced only random vocalizations.
B) They sang a recognizable version of the song of an ancestral sparrow species.
C) They sang a poorly developed version of their species' song.
D) They never sang at all.