搜尋結果
17 小時前 · The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radio navigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite systems (GNSS) that provide geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to ...
17 小時前 · Germany,[e] officially the Federal Republic of Germany,[f] is a country in the western region of Central Europe. It is the second-most populous country in Europe after Russia[g] and the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the south. Its 16 constituent ...
17 小時前 · Turkey, officially the Republic of Türkiye, is a country mainly in Anatolia in West Asia, with a smaller part called East Thrace in Southeast Europe.It borders the Black Sea to the north; Georgia, Armenia, Azerbaijan, and Iran to the east; Iraq, Syria, and the Mediterranean Sea (and Cyprus) to the south; and the Aegean Sea, Greece, and Bulgaria to the west.
3 天前 · The number π (/ p aɪ /; spelled out as "pi") is a mathematical constant that is the ratio of a circle's circumference to its diameter, approximately equal to 3.14159.The number π appears in many formulae across mathematics and physics.It is an irrational number, meaning that it cannot be expressed exactly as a ratio of two integers, although fractions such as are commonly used to ...
1 天前 · In probability theory and statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable.The general form of its probability density function is = ()The parameter is the mean or expectation of the distribution (and also its median and mode), while the parameter is its standard deviation.
3 天前 · Photosynthesis ( / ˌfoʊtəˈsɪnθəsɪs / FOH-tə-SINTH-ə-sis) [1] is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their activities.
1 天前 · Russia,[b] or the Russian Federation,[c] is a country spanning Eastern Europe and North Asia. It is the largest country in the world by area, extending across eleven time zones and sharing land borders with fourteen countries.[d] It is the world's ninth-most populous country and Europe's most populous country. Russia is a highly urbanized ...
