A) Yellowstone Park, he explained, which was the first wilderness to be set aside as a natural preserve anywhere in the world.
b) "Well", which Bradley said, "our knowledge has increased with time".
c) It's a perpetual claim that we know more today, which it's not borne out by facts.
d) What it also became inceasingly clear the Indian hunters of old had exerted a valuable ecological influence on the park lands.
J'espère t'avoir aidé :)