co-operate

bleeding

long-lived

drowning

throat

calves

conscious

streamlining

diving

hunting

head

skin

spinal column

flukes

grieve

sounding

shrinking

milk

mammary

teach

communicate

fins

drown

sickness

decompression

sound

disappearance

oceans

flippers

vocal

underwater

surfacing

cows

warm-blooded

hair

dive

dives

blubber

air

heart

blowholes

slapping

mammals

tail

breathe

spout

beached

lesions

calf

breaching

whale

learn

swimming

scheme

human

bulls

nurse

/pos

hearing