Complex sentence: Born in Lviv, Markhasev had come to the U.S. in 1989 with his mother, attending a program for gifted children in West Hollywood, where a teacher described him as well-liked and well-behaved.
Split into simpler sentences: Born in Lviv, Markhasev had come to the U.S. in 1989 with his mother. He attended a program for gifted children in West Hollywood, where a teacher described him as well-liked and well-behaved.