What geologic era is known as the age of mammals?

Explain: plate tectonics and people.

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory

In a river, which of the following would most likely be carried by suspension? this is called