How do start a conversation with significant other?

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

Which diagram represents the phase tha occurs after a solid melts?

The footprints of a dinosaur and the burrow of an ancient shrimp are examples of which kind of fossils