Complex sentence: In January 1990, Sur was taking part in a month-long Russian All-Stars skating tour in the U.S., headlined by Jayne Torvill and Christopher Dean, when he defected to the U.S. on January 24,1990.
Split into simpler sentences: In January 1990, Sur was taking part in a month-long Russian All-Stars skating tour in the U.S., headlined by Jayne Torvill and Christopher Dean. Sur defected to the U.S. on January 24,1990.