Which of the following describes the relationship between elements of an ecosystem

The answer is false.if you have any questions ask

Most topographic maps, the index contour lines are generally darker and are marked with their elevations. 

It's probably because the earth is actually tilted and is not straight when orbiting the sun. that's why when it's winter here, it's summer in the southern hemisphere. in the wintertime in the northern hemisphere, it's colder here because it's tilted away from the sun and the southern hemisphere is tilted closer to the sun (i believe this is the case anyways)

Some of the great contributes to advancement in the us were immigrants