计算二重积分 ，其中D 是由曲线 下一篇 Correct or improve the translation of the following Chinese sentences.原文：虽然美国多次声明恪守“一个中国”政策，但它应以实际行动来信守诺言，而不能食言。 译文：Although the US has reaffirmed many times that it adheres to the one-China policy, it should take actions that honor its words,
