In performing a contract, the parties shall avoid wasting resources, polluting the environment, and compromising ecology. 当事人在履行合同过程中，应当避免浪费资源、污染环境和破坏生态。 Where,after the contract becomes effective, there is no agreement in the contract between the parties on such content as quality, price or remuneration, place of performance etc.,or such agreement is ambiguous, the parties may agree upon supplementary terms through consultation; if a supplementary agreement cannot be reached, such terms shall be determined in accordance with the relevant provisions of the contract or usage of trade. 合同生效后，当事人就质量、价款或者报酬、履行地点等内容没有约定或者约定不明确的，可以协议补充；不能达成补充协议的，按照合同相关条款或者交易习惯确定。