THE GREAT WHITE SHARK, known more as a predator than a victim, will be placed on South Africa's list of endangered species because of threats from sport fishing and nets, the government said . . . AUTHORITIES IN CHINA'S southern city of Canton have executed 19 men convicted of murder and other serious crimes, including offenders as young as 18 and two criminal gang leaders, a government news agency reported Friday . . . PHILIPPINES PRESIDENT Corazon Aquino installed a new armed forces chief Friday despite opposition by a senior officer and said the turnover of command emphasized the rejection of insubordination in the military. Lt. Gen. Lisandro Abadia, 52, officially took over from Gen. Rodolfo Biazon, who retired at age 56 after three months at the helm of the 159, 000-member Armed Forces of the Philippines.