Fill in blank (iv).

Directions: In the following question, a passage is given with some words left out. Read the passage carefully and answer the given question.

Without water, no animal can ___(i)___. In desert regions the greatest ___(ii)___ to life is drying up. But, many creatures are able to make use of ___(iii)___ little water that exists in arid areas. One of nature’s masterpieces ___(iv)___ creatures equipped to ___(v)___ with desert life are the camels.