Answer:
are there any sentences to choose from
<span>. over a long period of time </span>
6. Lion
7.raccoon
8.rat
9. A keystone is a organism that helps define the entire ecosystem, and if the species were to disappear from the ecosystem no other species would be able to fill its ecological niche the ecosystem would be forced to radically change allowing new and possibly invasive species to populate the habitat.
The answer to your question should be a and c hope this helps
8 miles per hour. (Divide the 16 miles by the 2 hours traveled)