Choose or find odd pair of words - (Pistol : Gun) , (Knife : Dagger) , (Engine : Train) , (Car : Bus)

C. ENGINE : TRAIN

Choose or find odd pair of words - (Cockroach : Antennae) , (Lizard : Flagella) , (Hydra : Tentacles) , (Plasmodium : Cilia)

B. LIZARD : FLAGELLA

Choose or find odd pair of words - (Mercury : Sun) , (Moon : Earth) , (Star : Galaxy) , (Wheel : Axle)

C. STAR : GALAXY

Choose or find odd pair of words - (Sheep : Beat) , (Horse : Neigh) , (Ass : grunt) , (Owl : Hoot)

C. ASS : GRUNT

Choose or find odd pair of words - (China : Beijing), (Russia : Moscow), (Japan : Singapore), (Spain : Madrid)

C. JAPAN : SINGAPORE