4.Give reasons 
(a) Big cats have sharp teeth 
(b) Some monkeys have long prehensile tails 
(c) Penguins do not have air space in their bones 

4.[a] Big cats have sharp teeth to tear the fleshe
   [b] Some monkeys have long prehensile tails to grasp and hold branches.Prehensile means a tail adapted to grasp and hold objects
   [c] Penguins do not have space in their bones because these birds are flightless