question: When were the 18th and 19th satellites for the BeiDou system launched ?
answer: July 25 , 2015
turker_answer: The 18th and 19th satellites for the BeiDou system were launched on July 25 , 2015 .
rule-based: The 18th and 19th satellites for the BeiDou system were launched in July 25 , 2015 .