Which phrase best describes a biogeochemical cycle?�
◯ A. The movement of the chemical substance through Earth's bodies of water.
◯ B. The movement of the chemical substance between plants and animals.
◯ C. The movement of the chemical substance between the solid, liquid, and gaseous states of matter.
◯ D. The movement of the chemical substance through the biotic and abiotic parts of the Earth.
An asteroid hit the Yucatan Peninsula about 65 million years ago, filling the atmosphere with debris. How could this event have contributed to the extinction of dinosaurs?
◯ A. It blocked out sunlight.
◯ B. It sucked up all carbon.
◯ C. It caused Earth to overheat.
◯ D. It made it difficult to breath.
