question: What has helped geneologists researching slaves ?
answer: Colonial records of French and Spanish slave ships and sales , and plantation records in all the former colonies
turker_answer: Colonial records of French and Spanish slave ships and sales , and plantation records in all the former colonies have helped geneologists researching slaves .
rule-based: Colonial records of French and Spanish slave ships and sales , and plantation records in all the former colonies has helped geneologists researching slaves .