User:Shihhp/TWA/Earth

Science shows that Earth formed around 4.5 billion years ago. The organisms that live on Earth have completely changed its air (atmosphere); this is called a biosphere. 71% of Earth's surface is covered in salt water oceans. Earth is the only place in the Solar System where liquid water is known to exist at present. The other 29% is made of rocky land in the shape of continents and islands. Earth interacts with other objects in the Solar System, particularly the Sun and the Moon. The Earth orbits the Sun roughly once every 365.25 days. One spin is called a day and one orbit around the Sun is called a year. This is why there are 365 days in a year, but a leap day added to the calendar once every 4 years.

科學表明地球大約在45億年前形成. 生活在地球上的生物已經完全改變了它的空氣（大氣）. 這就是所謂的生物圈. 地球表面的71％被海水覆蓋. 地球是太陽系中目前唯一已知存在液態水的地方. 其餘29％是由大陸和島嶼形狀的多石土地製成. 地球與太陽系中的其他物體（特別是太陽和月亮）相互作用. 地球大約每365.25天繞太陽公轉一次. 一個自旋被稱為一天，圍繞太陽一個軌道被稱為一年. 這就是為什麼一年中有365天，但每4年將a日添加到日曆中的原因. 類型：