双方当事人没有履行合同中的义务。
Here is what I've found: many people don't hold themselves to a high standard and, therefore, go back on their word or don't fulfill obligations they say they'll fulfill.这是我发现的许多事情：许多人并没有以高标准来要求自己，所以他们总是不停地食言或并没有履行他们承诺履行的义务。
However, the Contractor may retain on Site, during the Defects Notification Period, such goods as are required for the Contractor to fulfill obligations under the Contract.但在缺陷通知期限内，承包商可在现场保留其根据合同完成规定义务所需要的此类货物。
