In the following passage some of the words have been left out, each of which is indicated by a number. Find the suitable word from the options given against each number and fill up the blanks with appropriate words to make the paragraph meaningful.

Pythons are  (1)  non-venomous snakes found ( 2)  in damp places or rocky ledges near marshes or in( 3)   They are considered to be the most primitive (4 )the living snakes, (5)  they retain the hind limbs of a (6) era in the form (7)  horny claw-like spurs, which are present( 8)  either side of  ( 9)   anus. These hind limbs are function less (10)   female pythons.