How many states are there now in what used to be called yugoslavia before 1991?

Which summarizes the relationship between density of an element and its distribution in earth? a. the greater an element’s density, the greater the amount of it found in the crust. b. the denser an elements is, the smaller the amount of it earth core. c. the greater an elements density, the smaller the amount of it’s found in the crust

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d

Based on what you know about the location of the earth in relation to the sun, why is this called the goldilocks zone in other galaxies? a. it's a region that exhibits a weak gravitational pull, thus maintaining a safe distance from the sun. b. it's an area that doesn't experience any major weather events that could cause mass extinctions. c. it's an area that's an optimal distance from the sun for potentially supporting life. d. it's a region that's unaffected by asteroid or meteor impacts.