Objective reasons. The reason why the National Natural Science Foundation of China applied to postpone the completion of the project was that the research plan could not be completed as scheduled due to objective reasons. Due to the local teaching practice and the current situation of class arrangement of the whole subject, the time required for project research is greatly limited. Submitted by the supporting unit to the counterpart science department for approval. Generally, only one extension is allowed, and the period is no more than two years. For postponed projects, those postponed on time shall be treated as normal.