Open bidding suppliers were selected and 2 out of 3 met the criteria. Public bidding refers to the use of public methods, publishing bidding announcements on the public media, and openly soliciting bids from the whole society for procurement. In the public bidding process, bidding documents refer to the documents on the regulations, conditions and requirements for bidding issued by the tenderer. During the public bidding process, suppliers need to submit bids in accordance with the conditions and requirements specified in the bidding documents, and the selected suppliers will be determined after bid evaluation. The criteria for choosing 2 out of 3 refer to the requirements in the bidding documents, and suppliers need to comply with the regulations and standards in the bidding documents.