Where would you be most likely to find the oldest rocks on earth?
in the middle of the highest mountains
in the middle of the continents
at the outer edges of oceanic crust
in the middle of the oceans

At the outer edges of ocean crust

Explanation:

The rocks found in continents are older and in some cases the oldest. The younger rocks are found in mid ridge of ocean. The oldest rocks can be found in ocean trenches that are very deep.

At the outer edges of ocean crust, oldest rocks can’t be found as relatively newer ones are formed continually and mostly found. So, different regions have different ages of rocks and needs to be explored properly.  

organisms that are both used in toothpaste as well as cause malaria are protista and monera.