Why
are two trails used for the race, each in alternate years ?

Every year they had to handle large numbers of people, dogs, fans, etc. In 1977, the board of directors made the decision to split the route into a Northern and Southern route and to alternate the route from year to year.

answer; ///(b) i believe that the correct answer is it could cause droughts which would make forest fire more likely; /// plz check this answer first, good luck

the precambrian aged rocks could be found in australia. australia is a region that has a lot of ancient civilization history from million years ago. in this region, there are a lot of recognizable fossils buried in its land which is considered a precambrian-aged rocks