Whenever the State of Nebraska, or any department or any agency thereof, any county board, county clerk, county highway superintendent, the mayor and city council or commissioner of any municipality, any entity created pursuant to the Interlocal Cooperation Act or the Joint Public Agency Act, or the officers of any school district, township, or other governmental subdivision, shall advertise for bids in pursuance of any statutes of the State of Nebraska, on any road contract work or any public improvements work, or for supplies, construction, repairs, and improvements, and in all other cases where bids for supplies or work, of any character whatsoever, are received for the various departments and agencies of the state, and other subdivisions and agencies enumerated in this section, they shall fix not only the day upon which such bids shall be returned, received, or opened, as provided by other statutes, but shall also fix the hour at which such bids shall close, or be received or opened, and they shall also provide that such bids shall be immediately and simultaneously opened in the presence of the bidders, or representatives of the bidders, when the hour is reached for the bids to close. Such bids may be withheld from disclosure until an intent to award is issued. If bids are being opened on more than one contract, the officials having in charge the opening of such bids may, if they deem it advisable, award each contract as the bids are opened. Sections 73-101 to 73-106 shall not apply to the State Park System Construction Alternatives Act or sections 39-2808 to 39-2823.