Read Grade-Level Informational Texts Practice Test

Read the passage. The Grand Canyon is one of Earth's most spectacular natural wonders. Located in Arizona, this enormous canyon stretches 277 miles long and reaches depths of over a mile. The Colorado River carved the canyon over millions of years through a process called erosion. Water, wind, and ice slowly wore away layers of rock, creating the canyon's distinctive colorful walls. Geologists can see rock layers that are nearly two billion years old at the canyon's bottom. The different colored layers represent different time periods in Earth's history. Millions of visitors travel to the Grand Canyon each year to witness this ancient geological marvel. Why did the Grand Canyon get its shape over time?

Read the passage. Solar panels convert sunlight into electricity that powers homes and businesses. Each panel contains special cells made from silicon, a material that can capture light energy. When sunlight hits these photovoltaic cells, it knocks electrons loose from atoms. The moving electrons create an electric current, which flows through wires. An inverter changes this electricity from direct current to alternating current, the type used in buildings. Solar panels work most efficiently when positioned to receive maximum sunlight throughout the day. Many people install solar panels on rooftops to reduce their electricity bills and decrease pollution. As technology improves, solar energy becomes increasingly affordable and popular. How does solar power get used in buildings?