Under the common counts the pleader need allege only that he is suing for unjust enrichment , for labor performed or for goods sold and delivered or services rendered but not paid for .
根据一般诉讼理由,原告只需宣称他所起诉主张的是(对方的)不当得利,已经付出的劳动,或已经出售并交付的货物,或已经提供服务但对方尚未支付价款。