A lactic acid test is a blood test that measures the level of lactic acid made in the body. Most of it is made by muscle tissue and red blood cells.
A biofuel is a fuel that is produced through contemporary biological processes, such as agriculture and anaerobic digestion, rather than a fuel produced by geological processes such as those involved in the formation of fossil fuels, such as coal and petroleum, from prehistoric biological matter.
Introduction. By biofuels on this page, I mean fuels for vehicles, such as biodiesel and bioethanol - although you can also use the term biofuel to cover any kind of fuel made from living materials or their waste. Biogas is another biofuel which can be used to power vehicles, and is covered on another page.