Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air. Other processes used to convert fuel into energy include various other exothermic chemical reactions and nuclear reactions, such as nuclear fission or nuclear fusion. Fuels are also used in the cells of organisms in a process known as cellular respiration, where organic molecules are oxidized to release usable energy. Hydrocarbons are by far the most common source of fuel used by humans, but many other substances, such as radioactive metals, are currently used as well .

Chemical fuels are substances that release energy by reacting with substances around them, most notably by the process of oxidation.

Biofuel can be broadly defined as solid, liquid, or gas fuel consisting of, or derived from biomass. Biomass can also be used directly for heating or power—known as biomass fuel. Biofuel can be produced from any carbon source that can be replenished rapidly e.g. plants. Many different plants and plant-derived materials are used for biofuel manufacture.

Agnes Caroline Thaarup Obel (born 28 October 1980 in Gentofte (north of Copenhagen) is a Danish singer/songwriter. Her first album, Philharmonics, was released by PIAS Recordings on 4 October 2010 in Denmark, Norway, Germany and other European countries. Since June 2011, Philharmonics is certified gold by the Belgian Entertainment Association (BEA) for sales of 10,000 units. At the Danish Music Awards in November 2011, Agnes Obel won five prizes for: Best Album Of The Year, Best Pop Release Of The Year, Best Debut Artist Of The Year, Best Female Artist Of The Year and Best Songwriter Of The Year.

Obel, and her younger brother Holger, grew up in an unconventional environment. Her father had three children from another marriage. He loved to collect strange objects and instruments like the xylophone and the double bass. Her mother, Katja Obel, was a jurist but also a brilliant musician. She used to play Bartók and Chopin on the piano. With a house full of sound and music : Agnes Obel learned piano at a very young age. During her childhood, Agnes Obel found inspiration in Jan Johansson's work. Johansson's songs, European folk tunes done in a jazzy style, have influenced the young musician a lot.

Michael "Mike" Robert Chang, Jr. is a fictional character from the Fox musical comedy-drama series Glee. The character is portrayed by actor and dancer Harry Shum, Jr., and has appeared on Glee since the fourth episode in the first season, "Preggers", first broadcast on September 23, 2009. Glee follows the trials of the New Directions glee club at the fictional William McKinley High School in the town of Lima, Ohio, of which Mike is a member. He is introduced as a football player who joins the club together with a few of his teammates, and quickly shows himself to be an excellent dancer.

Mike is played by Harry Shum, Jr. He has also been portrayed as a very young boy by Evan Kishiyama in the episode "The Substitute". When Shum was hired, he had been through the audition process, but as far as he knew "it was just like a regular acting gig where you go on for a day." In an interview with the New York Post, he elaborated, "I got hired as a day player and it turned into a week, and then a month and so on. I was just rolling with it—I mean, who would say no to that?"