Which of the following is not an aquatic animal?

Which among the following have an open circulatory system?
$(i)$ Arthropoda
$(ii)$ Mollusca
$(iii)$ Annelida
$(iv)$ Coelenterata

You are given leech,Nereis,Scolopendra,prawn,and scorpion; all have a segmented body organization. Will you classify them in one group? If no,give the important characters based on which you will separate these organisms into different groups.

Classify the following animals based on the number of chambers in their heart: Rohu,Scoliodon,Frog,Salamander,Flying lizard,King Cobra,Crocodile,Ostrich,Pigeon,Bat,Whale.

State the importance of classification.

Write true or false for the following statement:
The animals belonging to phylum $Mollusca$ have a peculiar water-driven tube system that they use for moving around.