In 1983, the metre was redefined in the International System of Units (SI) as the distance travelled by light in vacuum in 1/ 7008299792458000000â 299792458 of a second. As a result, the numerical value of c in metres per second is now fixed exactly by the definition of the metre.
Blattodea is an Order of insects containing the cockroaches. Cockroaches first evolved around 350-300 million years ago and are probably one of the most despised of all insects. For some people the mere mention of cockroaches will send them running for cover.
Mulatto is a term used to refer to persons born of one white parent and one black parent or to persons born of a mulatto parent or parents. In English, the term is today generally confined to historical contexts. English speakers of mixed white and black ancestry seldom choose to identify themselves as mulatto.