The trustees shall furnish to each bidder a standard proposal form, which, when filled out and executed, may be submitted as the bid. Bids not presented on forms so furnished shall be disregarded. The trustees shall not furnish proposal forms to any person who is required to submit and has not submitted a questionnaire and financial statement for prequalification at least five days prior to the date fixed for publicly opening sealed bids and been prequalified for at least one day prior to that date.