A thick layer of blubber (fat), up to 11 cm (4.3 in.) thick, keeps the polar bear warm while swimming in cold water (Stirling, 1988).
(A thick layer of blubber (fat), up to 11 cm (4.3 in.) thick; keeps; the polar bear; T:while swimming in cold water)
A thick layer of blubber (fat), up to 11 cm (4.3 in.) thick
keeps
the polar bear T:while swimming in cold water