Now the following four methods are used to purchase grain : the state purchases grain through xed quotas ; the state purchases grain through negotiations with producers ; grain - processing enterprises purchase grain from the wholesale markets ; and farmers sell their grain at fairs 目前糧食收購(gòu)主要有四種形式:國(guó)家定購(gòu)、國(guó)家議購(gòu)、糧食加工企業(yè)在批發(fā)市場(chǎng)上購(gòu)買和農(nóng)民在集市上銷售。