Letâs start with military unmanned aircraft. According to the annual almanac published by the Air Force Association (http://www.airforcemag.com/Magaz...), as of mid-2016: MQ-1 Predators: 268 produced, 139 in service, 111 destroyed in accidents; MQ-9 Reapers: 346 (including those as yet undelivered), 165 in service, 24 destroyed in accidents
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.In contrast to excretion, the substance may have a certain function, rather than being a waste product.ecretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.
In prokaryotes, such as bacteria, secretion occurs by releasing substances from the bacterial cell interior to its external environment. Word origin: Latin secretio, from secernere (to secrete). Compare: 1  excretion.