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.
How your kidneys are checked. Two tests are used to check for kidney disease. 1  A blood test checks your GFR, which tells how well your kidneys are filtering. 2  A urine test checks for albumin in your urine, a sign of kidney damage.