How do animals obtain the nitrogen they use to make proteins and nucleic acids?
a. by consuming plants or other animals
b. by absorbing ammonia from bacteria growing in the roots of plants
c. by breathing the nitrogen present in the atmosphere
d. by absorbing nitrogen found in the soil

The steps in the formation of extrusive igneous rocks are listed below in an incorrect order: 1. rock melts due to high temperature. 2. rock is buried deep under earth's surface. 3. magma is forced out of earth's surface during volcanic eruption. 4. lava cools and crystallizes to igneous rock. which of these best shows the correct order of steps in the formation of extrusive igneous rocks? 1, 3, 4, 2 2, 1, 3, 4 3, 4, 2, 1 4, 2, 1, 3