Free Grade 7 Reading Comprehension Passages & Answers

Nestled high in the Andes Mountains of Peru lies Machu Picchu, a breathtaking stone citadel built by the Inca Empire in the 15th century. For centuries, the outside world knew nothing of its existence. In 1911, an American explorer named Hiram Bingham organized an expedition to find the last capital of the Inca. Guided by local indigenous farmers, Bingham stumbled upon the overgrown ruins of Machu Picchu. He famously publicized it as the “Lost City of the Incas.” However, this title is a historical misconception. The city was never truly lost; the indigenous families living in the surrounding valleys had known about the magnificent ruins all along.

Before the Industrial Revolution in England, the vast majority of peppered moths had light, speckled wings. This coloration provided perfect camouflage against the light-colored bark of the local trees, hiding them from hungry birds. However, as factories began burning massive amounts of coal, dark soot blanketed the forests, turning the tree trunks black. Suddenly, the light-colored moths stood out and were easily eaten. Meanwhile, a rare genetic mutation had produced a few dark-colored moths. Against the soot-covered trees, these dark moths were perfectly camouflaged. They survived, reproduced, and passed their dark coloring to their offspring. This famous event is a textbook example of “natural selection” in action.

Clara had always felt a strange draft coming from the massive oak bookshelf in her grandfather’s study. One rainy afternoon, she decided to investigate. She ran her fingers along the dusty spines of the encyclopedias until she noticed one book that seemed oddly clean: a thick, leather-bound copy of The Odyssey. When Clara pulled the book, she heard a heavy metallic click. To her astonishment, the entire bookshelf swung inward on hidden hinges. Clara stepped into a dimly lit, secret room. It was filled with ancient maritime maps, a large brass telescope, and a glowing, intricately carved globe. It seemed her grandfather had lived a life far more adventurous than he had ever admitted.

When you stream a video or download a file on the internet, that data travels across the globe in a fraction of a second. This incredible speed is made possible by fiber optic cables. Unlike traditional copper wires that transmit data using electrical currents, fiber optic cables are made of incredibly thin strands of pure glass. They transmit data using rapid pulses of laser light. But how does the light stay inside a curved cable without shooting out the sides? The glass strands are coated in a special material that acts like a mirror. This creates a phenomenon called “total internal reflection,” causing the light to bounce off the inner walls and travel perfectly down the cable over vast distances.

For decades, scientists believed that all life on Earth relied entirely on the sun for energy. This theory was shattered when oceanographers discovered hydrothermal vents—geysers of superheated, mineral-rich water erupting from the ocean floor in total darkness. Despite the crushing pressure and lack of sunlight, these vents are teeming with life, including giant tube worms and ghost crabs. The foundation of this alien ecosystem is a unique type of bacteria. Instead of using sunlight to make food (photosynthesis), these bacteria use the toxic chemicals spewing from the vents, like hydrogen sulfide, to produce energy. This remarkable biological process is known as chemosynthesis.