In the past earths sea level has sometimes been lower at that time which of the following would have been a major difference in the ocean basins

The answer is mid-ocean rid would have been chains of mountains hopefully this helps!

tracks, burrows, eggshells, nests, tooth marks, or gastroliths

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).