20xx小學(xué)生五年級上冊英語手抄報(bào)素材模板(參考版)
2025-03-25 22:24本頁面
【正文】 C2Rainbow彩虹A rainbow is an optical and meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicolored arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.In a primary rainbow, the arc shows red on the outer part and violet on the inner side. This rainbow is caused by light being refracted (bent) when entering a droplet of water, then reflected inside on the back of the droplet and refracted again when leaving it.In a double rainbow, a second arc is seen outside the primary arc, and has the order of its colors reversed, red facing toward the other one in both rainbows. This second rainbow is caused by light reflecting twice inside water droplets.ThunderThunder is the sound caused by lightning. Depending on the distance and nature of the lightning, thunder can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within a bolt of lightning. In turn, this expansion of air creates a sonic shock wave, similar to a sonic boom, which produces the sound of thunder, often referred to as a clap, crack, or peal of thunder. The distance of the lightning can be calculated by the listener based on the time interval from when the lightning is seen to when the sound is cause of thunder has been the subject of centuries of speculation and scientific inquiry. The first recorded theory is attributed to the Greek philosopher Aristotle in the thirdcentury BC, and an early speculation was that it was caused by the collision of clouds. Subsequently, numerous other theories were proposed. By the mid19th century, the accepted theory was that lightning produced a vacuum. (From Wikipedia )lt。B4Nature, in the broadest sense, is equivalent to the natural, physical, or materialworld or universe. Nature refers to the phenomena of the physical world, and also to life in general. It r
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