We point out that in the first order time-dependent perturbation theory. the transition probability may behave nonsmoothly in time and have kinks periodically. Moreover. the detailed temporal evolution can be sensitive to the exact locations of the eigenvalues in the continuum spectrum. https://olivebookmarks.com/story19598850/the-development-of-knowledge-enrichment-books-concerning-ice-and-snow-physical-studies-for-high-school-students