On 15th May, 2010, a Chinese company offered to a French company, “sell 10000 Qing Yan Brand bicycles, Article No.171069, FOB Shanghai USD 100 per set, shipment during July, 2010. Subject reply here on or before 20th May, 2010. ...... ”.On 17th May, 2010, the French company replied by FAX, “ we accept your offer dated 15th May, 2010, but at the price of FOB Shanghai USD 80 per set, shipment during October, 2010.”The Chinese company hadn’t replied to the French company and sold their bicycles to another foreign company.However, on 19th May, 2010, the French company replied by FAX again, “ we completely accept your offer dated 15th May, 2010.” The Chinese company replied to the French company at once by FAX, “we have sold the bicycles to others. We will offer you in the future as possible as we can.”But the French company thought that the contract has been concluded and required the Chinese company to ship the bicycles during July, 2010 at Shanghai port.According to CISG, do you think the above two companies have concluded a contract? (达成/没达成) (注意:答题时请直接根据题目后面的可选项目进行选择，不用说明理由，否则机器可能不会识别)