Why are invasive species dangerous to the environment?

Asap! how does the distance between two objects affect the force of gravity? how is the moon dependent on the sun?

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

What occurs to the cell during mitosis