Which of the following statements are correct?

(i) The gradual and fairly predictable change in the species composition of a given area is called ecological succession.

(ii) During succession some species become more numbers, whereas populations of other species decline and even disappear.

(iii) The entire sequence of communities that successively change in a given area are called sere(s).

(iv) The individual transitional communities are termed seral stages or seral communities.

(v) Succession is a process that starts where no living organisms are there.

(vi) Areas where no living organisms ever existed, say bare rock; secondary succession occurs.

(vii) In across that somehow, lost all the living organisms that existed there primary succession occurs.