Answer the following question given this paragraph: Volcanic mountain ranges form when oceanic crust subducts into the mantle at convergent plate boundaries. The Andes Mountains are a chain of coastal volcanic mountains. They are forming as the Nazca plate subducts beneath the South American plate ( Figure below ). Q: What forms when oceanic crust subducts into the mantle at convergent plate boundaries? Choices: - tsunamis - glaciers - coral - volcanic mountain ranges A:
volcanic mountain ranges

Answer the following question given this paragraph: For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star!. Q: For a star to form, what force pulls gas and dust into the center of the nebula? Choices: - weight - centrifugal force - motion - gravity A:
gravity

Answer the following question given this paragraph: Although air can transfer heat rapidly by convection, it is a poor conductor and thus a good insulator. The amount of available space for airflow determines whether air acts as an insulator or conductor. The space between the inside and outside walls of a house, for example, is about 9 cm (3.5 in) large enough for convection to work effectively. The addition of wall insulation prevents airflow, so heat loss (or gain) is decreased. Similarly, the gap between the two panes of a double-paned window is about 1 cm, which prevents convection and takes advantage of air's low conductivity to prevent greater loss. Fur, fiber, and fiberglass also take advantage of the low conductivity of air by trapping it in spaces too small to support convection, as shown in the figure. Fur and feathers are lightweight and thus ideal for the protection of animals. Q: Although air can transfer heat rapidly by convection, it is a poor conductor and thus a good what? Choices: - magnet - absorber - transporter - insulator A:
insulator