Free Grade 8 Reading Comprehension Worksheet & Answers

Launched in December 2021, the James Webb Space Telescope (JWST) represents a monumental leap in astrophysics. Unlike its predecessor, the Hubble Space Telescope, which primarily observes visible light, the JWST is optimized for infrared astronomy. Because the universe is constantly expanding, the light from the very first galaxies formed after the Big Bang has been stretched as it traveled through space over billions of years. This stretching phenomenon, known as “redshift,” shifts the ancient light out of the visible spectrum and into the infrared. By detecting these faint infrared signals, the JWST acts as a cosmic time machine, allowing astronomers to observe the universe exactly as it appeared over 13.5 billion years ago.

The air in the abandoned Victorian mansion was thick with the scent of decaying wood and damp earth. Arthur’s flashlight beam cut through the pervasive gloom, illuminating dust motes that danced like tiny phantoms in the cold drafts. He had been exploring the ground floor for an hour, finding nothing but rotting furniture, when he noticed a narrow, arched doorway perfectly concealed behind a crumbling tapestry. His heart hammered against his ribs as he turned the rusted brass handle. The hinges screamed in protest, revealing a room completely untouched by the ravages of time. In the center sat a pristine mahogany desk, upon which rested a single, freshly lit candle.

The Silk Road was not a single, paved highway, but rather a vast, complex network of interlocking trade routes connecting China and the Far East with the Middle East and Europe. Established during the Han Dynasty (207 BCE – 220 CE), these routes spanned over 4,000 miles of treacherous terrain, including the Gobi Desert and the Pamir Mountains. While lucrative commodities like Chinese silk, Indian spices, and Roman glassware traversed these paths, the Silk Road’s greatest legacy was cultural and intellectual exchange. Technologies such as paper-making and gunpowder moved westward, while philosophies like Buddhism spread eastward. Unfortunately, the route also facilitated the rapid transmission of disease, most notably the bubonic plague, which devastated Europe in the 14th century.

CRISPR-Cas9 is a revolutionary genetic engineering tool that allows scientists to precisely edit DNA. Adapted from a natural defense mechanism found in bacteria, CRISPR works like a pair of molecular scissors, targeting a specific sequence of DNA and slicing it open so that genetic material can be added, removed, or altered. The potential medical applications are staggering. Researchers believe CRISPR could eventually cure genetic disorders like cystic fibrosis or sickle cell anemia by simply rewriting the patient’s flawed genetic code. However, the technology has sparked fierce ethical debates. Critics warn that altering human DNA, particularly in embryos, could lead to unforeseen biological consequences and raises the controversial prospect of “designer babies,” where genetic traits are selected for aesthetic rather than medical reasons.

For decades, neuroscientists believed that the adult human brain was a static organ; it was thought that once a person reached adulthood, the brain’s physical structure was fixed and it could no longer generate new neural pathways. This paradigm was shattered by the discovery of “neuroplasticity.” Neuroplasticity is the brain’s remarkable ability to reorganize itself by forming new synaptic connections throughout life in response to learning, experience, or injury. For example, if a person loses their sight, the brain can rewire the visual cortex to heighten the senses of hearing and touch. This adaptability explains why humans can learn new languages late in life and how stroke victims can often regain lost motor functions through intensive rehabilitation.