Given below are four statements $(a-d)$ each with one or two blanks. Select the options which is correctly fill up the blanks into two statements.

$(a)$ Ecological succession is a...$(i)$... and fairly predictable changes in the ....$(ii)$... of a given area

$(b)$ Ecological succession, entire sequence of communities that successively change in given area are called ...$(i)$....

$(c)$ Primary succession occurs on...$(i)$...

$(d)$ Secondary succession is ...$(i)$... than primary succession

• A

  $a - (i)$ gradual, $(ii)$ - Species composition $b- (i)$ Sere

• B

  $b - (i)$ Climax $c- (i)$ Newly cooled lava, bare rock

• C

  $a - (i)$ fast, $(ii)$ - Species composition $c- (i)$ Cut forests

• D

  $c- (i)$ Lands that have been flooded $d - (i)$ slower