The scientific theory contains many steps. It could also be known as a hypothesis. Hope this is helpful
A simple columnar epithelium<span> is a </span>columnar epithelium<span> that is uni-layered. In humans, a simple </span>columnar epithelium<span> lines most </span>organs<span> of the digestive tract including the stomach, small intestine, and large intestine. Simple columnar epithelia line the </span>uterus<span>.</span>
Greenhouse gases arise naturally, and are part of the make-up of our atmosphere. Earths conditions are just right to allow life, including us, to flourish. Part of what makes Earth so amenable is the naturally-arising greenhouse effect, which keeps the planet at a friendly 15 °C (59 °F) on average. But in the last century or so, humans have been interfering with the energy balance of the planet, mainly through the burning of fossil fuels that give off additional carbon dioxide into the air. The level of carbon dioxide in Earth’s atmosphere has been rising consistently for decades and traps extra heat near the surface of the Earth, causing temperatures to rise.
