(1) The hills are covered in lush green vegetation.
(2) The inn has a garden of semi-tropical vegetation.
(3) ...a smell of gently-rotting vegetation.

(1) a suitable candidate
(2) This programme is not suitable for children.
(3) a suitable place for a picnic

(1) a flat/sloping roof
(2) a thatched/slate, etc. roof
(3) The corner of the classroom was damp where the roof had leaked.

(1) Several presidents attended the funeral.
(2) the president of the United States
(3) president Bush is due to visit the country next month.

(1) We've got a spare bedroom, if you'd like to stay.
(2) I'm afraid I haven't got any spare cash .
(3) Are there any tickets going spare (= are there any available, not being used by sb else) ?

(1) a black and white spotted dress
(2) a leopard's spotted coat
(3) ...hand-painted spotted cups and saucers in green and blue...

(1) underwater creatures
(2) an underwater camera
(3) Take a deep breath and see how long you can stay underwater.

(1) tropical swamps
(2) swampy ground
(3) The department was swamped with job applications.

(1) policies that will benefit society as a whole
(2) Racism exists at all levels of society.
(3) They carried out research into the roles of men and women in today's society.

(1) a tiny baby
(2) Only a tiny minority hold such extreme views.
(3) The living room is tiny...