An association football (soccer) match is presided over by a referee, whom the Laws of the Game give full authority to enforce the Laws of the Game in connection with the match to which he has been appointed (Law 5). The referee is oftentimes assisted by two assistant referees, and sometimes by a fourth official.
Barfoed's test. Barfoed's test is a chemical test used for detecting the presence of monosaccharides. It is based on the reduction of copper(II) acetate to copper(I) oxide (Cu2O), which forms a brick-red precipitate.
The fecal occult blood test (FOBT) is a lab test used to check stool samples for hidden (occult) blood. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum â though not all cancers or polyps bleed. Typically, occult blood is passed in such small amounts that it can be detected only through the chemicals used in a fecal occult blood test. If blood is detected through a fecal occult blood test, additional tests may be needed to determine the source of the bleeding. The fecal occult blood test can only detect the presence or absence of blood â it doesn't indicate potential sources of bleeding.