Simplify the following text for a Grade 6 native English-speaking person.
Original: On August 13 , 1943 , Graham married Wheaton classmate Ruth Bell ( 1920 â `` 2007 ) , whose parents were Presbyterian missionaries in China , where her father , L. Nelson Bell , was a general surgeon .
Simplified: Her parents were Presbyterian missionaries in China . Her father , L. Nelson Bell , worked as a surgeon there .