Which structure carries blood to the heart so the heart has its own supply of oxygen and nutrients to perform its function?

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight. which of these is most likely effect on the ecosystem?

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

The means by which a cell transports large molecules out of the cell is called