The invention of the , 150 years ago, was one of the most in history. This new form of light, light, brightened and made safe once-dark streets, prolonged hours into the evening, and brought electricity into homes for the very first time. Today, this glow has grown, but at a cost. is the over-illumination of cities and night skies by artificial lighting. It's caused by the abundance of light sources emitting light outside of an . Several types of light pollution exist, including , which is a disruptive light that shines horizontally, light trespass, the unwanted shining of light onto nearby areas, and sky glow, a halo over inhabited areas caused by the scattering of light particles. No matter what form light pollution takes, each can have unintended, yet . Wildlife, particularly sea turtles, have had their disrupted. The turtle hatchling's instinct to follow the light of the moon in order to reach the sea is by the light of inland cities. Because of this, many never find their way to the ocean.

Human's well-being is also compromised by light pollution. The excess light can overwhelm in the retina, damaging one's eyesight. Plus, it disrupts natural sleep cycles, and causes sleep deprivation, leading to a number of health problems, possibly including cancer. Light pollution also results in the production of additional . Each year, potentially worth of coal or oil, which are burned to produce electricity, are wasted on . Over the past several decades, light pollution in North America has increased an estimated 6 to 10% each year. A fueled by growing populations, greater access to electricity, and increased urban development. Efforts have been made to help this rise in excess light, including the development of alternative energy-efficient light bulbs and smarter directional lighting designs. These and other innovations will continue to refine this 150-year-old technology, artificial light, and optimize it, for a brighter future.

1. Which new words/phrases were easiest to remember? Give three.

どの語句/文が覚えやすかったですか？３つ挙げてください。

どの語句/文が話したり理解するのに難しかったですか？３つ挙げてください。