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.