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3. Physical period: Uniform circular motion is a kind of periodic motion. The so-called periodicity refers to the fact that after a certain period of time, the moving object repeats back to its original position, and the instantaneous speed repeats back to its original size and direction. The time it takes for an object to move in a uniform circle is called a period. The period is expressed by the symbol T, and the period is also a physical quantity describing the speed of uniform circular motion. The long period indicates the slow motion of the object, while the short period indicates the fast motion of the object.杨长帆深知，既然沙加路先来了，对方还是不愿真打，不如听听他们开出的价码：说吧，怎么个和平法。十万年前，仙界诛仙混战，众神陨落，一本暗藏玄机的《生死天书》落入人间。青年考古学家陆云在一次科考中无意中闯入一间根本无法辨别年代的墓室，至此平静的生活被打破，开始了寻找各种谜团的惊险历程。Although it is more worry-free and labor-saving to choose a decoration company for decoration, there will also be drawbacks. Many people will no longer ask about the decoration after handing it over to the decoration company, and it is wrong to wait for acceptance. Because some informal decoration companies will have a series of phenomena such as deliberate charging, project quality problems, slow project progress and excessive project costs. Therefore, even if the decoration company is chosen for decoration, it is necessary to go to the construction site at any time to keep an eye on the work.张杨摇头道：爹，娘，皇帝召见，怎能不去呢？秦枫问张杨道：可是为了葫芦和板栗的亲事？张杨点头。所为何事，要知道张家和郑家与镇国公府并无过深来往。