Sheffield is a big city in a region called South Yorkshire in the North of England. 534,500 people live there. Sheffield is in the middle of lots of hills. The city centre is where the River Sheaf meets the River Don, and Sheffield gets its name from the River Sheaf. The city is east of the Peak District National Park. It is estimated that Sheffield has over two million trees, which is more than any city in Europe per each person. 61% of the city is green space, such as parks and forests.
The area of Sheffield used to be the Anglo-Saxon shire of Hallamshire, the city itself was founded later.
Sheffield is famous for making cutlery (like knives and spoons). People in Sheffield have made cutlery for a very long time (a Sheffield-made knife is referred to in Chaucer's "Canterbury Tales", a book from the Middle Ages). Sheffield is also famous for making steel. Benjamin Huntsman discovered the crucible technique for making steel in 1740. In 1856, Henry Bessemer invented the Bessemer converter steelmaking furnace. Henry moved to Sheffield to make steel. Later, in 1912, Harry Brearley invented stainless steel in Sheffield.
The first football team in the world is from Sheffield, Sheffield F.C., set up in 1857. Sheffield currently has two big professional football teams, Sheffield Wednesday and Sheffield United.
There are lots of famous bands from Sheffield. Some of them are Pulp, the Human League, Def Leppard and the Arctic Monkeys. Michael Palin is also from Sheffield.
There is a big arena called the Motorpoint Arena in Sheffield. WWE have visited this arena to do live shows.
Fertilizer
A fertilizer is a chemical that helps plants to grow. It is used to replace the mineral salts taken by plants or removed/washed away by rain.
Common fertilizers:
The important things in fertilizer are:
When fertilizers are offered for sale, the percentage of N, P, and K must be written on the bags or boxes, but for historcal reasons, P is shown as %P2O5 and K is shown as %K2O.
E.g.:9-23-30 which means: 9% N, 23%P2O5 and 30%K2O.
In Australia the pecent of elemental sulfur must also be shown.
In the UK, the elemental composition (in percentages) may also be shown alongside the mandatory traditional system, provided the numbers are put inside square brackets.
Leafy plants need lots of N. Flowering plants need lots of P and K.
A soil test can tell how much N, P, and K is needed.
Military
The military is the group or groups of people that are given power to defend something (mostly a country). They are armed, so they are called the armed forces. The military protects its country by defending it from the armed forces of enemies, if there is a war. The military can also be ordered by the government of the country to attack another country. The word "military" comes from Latin "miles", warrior.
There are many jobs to do in a military. Some jobs are for fighting and some are for other work to support the military. Some things people do in the military are use weapons, drive vehicles, and repair weapons. Other people in the military learn how to fly aircraft, pilot ships, or repair engines. People in the military usually wear clothes called a uniform. In some places, especially where there may be combat, a uniform often comes in a camouflage pattern which is designed to make the person hard to see in the forest or desert.
There are two ways to join the military. In many countries, people join the military because they want to. In other countries, there are laws that some people have to be in the military, even if they do not want to be. This is called "the draft" or "conscription". It usually depends on age and physical fitness. Old military people or former military people are called "veterans". Some are members of a military reserve force.
The military of a country is usually divided into different branches organizations that do different kinds of work. These branches usually are:
Sometimes the military has more branches that do more specialized work. For example, in the United States and United Kingdom there are:
Some big countries even have small units which perform special actions which are very difficult. They are called special forces.
There are also mercenaries, soldiers who fight just for pay and have little loyalty to whomever might hire them, and private military contractors (PMC), which are under the command of a company (civilian company). The Medieval Italian "condottieri" were a historical example of PMCs. A warlord may have a private army, which are often no more trustworthy than common gangsters or criminals.
In most countries of the world, young men and (in a few countries) women between 17 and 18 and of good health may be forced by the government of their country to join the military and have military training. This is called "conscription". The countries that do not have conscription include Australia, Bangladesh, Canada, France, Hungary, India, Italy, Japan, Malta, New Zealand, Saudi Arabia, Slovenia, South Africa, Spain, and the United Kingdom. In some countries, such as Argentina and United States, conscription is legal but is not used, at the present time.
When a person wants to join the military as a volunteer, they "enlist". (This means simply that they put their name on a list.) They have to be above a certain age, 17 or 18 in most countries. They have to pass physical fitness tests to show that they are well enough to do the jobs that they will have to do. They must also have good enough hearing, to hear orders, and good enough sight to use a rifle.
New people in the military are often called “recruits”. They have training at a special camp, sometimes called “boot camp" or "basic training". During this training, the recruits usually have very little free time. They learn to understand the "orders" or "commands" that are given by the officers to the "troops". (The troops are the military people in a group.) They learn the right ways to obey the orders. They do a lot of exercise to improve their fitness and strength. They learn about weapons, first aid, and their uniforms and "kit". (Their kit is their equipment.) Recruits also learn how to march. (This is the way to walk together, keeping "in step".) Learning to march is sometimes called “drill”. By the time soldiers finish "boot camp", they should know enough to be a helpful person in their group. The camp usually finishes with a parade in which the newly trained recruits show off their marching and other skills they have learned in front of important visitors. Once the recruits are fully trained, they are ready to defend (protect) their country from attack, or to go to [war], if necessary.
<nowiki>*</nowiki>includes 169,800 Marine Corps
<nowiki>**</nowiki>includes Strategic Deterrent Forces, Paramilitary, National Guard, etc.
<nowiki>***</nowiki>includes 125,000 Revolutionary Guards
Photosynthesis
Photosynthesis is the process by which plants and some microorganisms make substances like carbohydrates. It is an endothermic (takes in heat) chemical process that uses sunlight to turn carbon dioxide into sugars. The sugars are used by the cell as energy, and to build other kinds of molecules.
Photosynthesis is very important for life on Earth. Green plants build themselves using photosynthesis. Algae, protists and some bacteria also use it. Some exceptions are organisms that directly get their energy from chemical reactions; these organisms are called chemoautotrophs.
Photosynthesis can happen in different ways, but there are some parts that are common.
Photosynthesis occurs in the chloroplasts in leaves (or other green tissues). They contain chlorophyll, the green pigment that absorbs light energy. In leaves, palisade cells have chloroplasts to capture light.
Oxygen is a waste product of photosynthesis: it comes out of the plant in respiration. All the oxygen in the atmosphere has its origin in plants (including those microorganisms which do photosynthesis)