July 14, 1988

LEAD: Vice President Bush, seeking the political spotlight at a time when the Democrats are dominating the news, will address the United Nations Security Council Thursday in a debate over the downing of an Iranian airliner by an American warship, the White House announced today.

LEAD: HORTICULTURALLY, the United States is in many ways still a colony of Britain. American gardeners who travel eventually find their way to the Chelsea Flower Show in London and make pilgrimages, sometimes repeatedly, to Sissinghurst, Hidcote and other celebrated British gardens.

LEAD: This was no ordinary Sunday sermon.

LEAD: TOLD that she looked too young to have voted for Franklin D. Roosevelt more than once, Sylvia Schauman tugged on the hem of her skirt and smiled like a Ziegfeld girl. ''I know, I know,'' she said. ''Everyone tells me that.''

LEAD: The Digital Equipment Corporation is reported to be close to an agreement to use in its computers an advanced microprocessor chip designed by a Silicon Valley company. Use of the chip would be a rare move away from Digital's own private hardware standard.