U.S. IMPORTS FROM CHINA surged in 1990 to a record $15.1 billion, with the bulk of the increase coming in clothes and shoes, the U.S. International Trade Commission reported . . . TWO NEPHEWS of black South African leader Nelson Mandlea, deputy president of the African National Congress, were killed in black township violence this week, the ANC said Friday . . . A STRONG EARTHQUAKE occurred Friday in the Pacific Ocean off Japan's east coast, the Central Meteorological Agency said. No injuries or damage were reported, and there was no danger of tsunami seismic waves because the epicenter was 290 miles below the sea floor 160 miles south of Torishima, the agency said.