Last Friday as I nearly cycled halfway to school, I suddenly discovered my bike's back wheel tire got flat. At once I concluded that it must have been punctured somewhere. This greatly upset me for I had to cover the left distance which was about over 5 kilometers on foot. Moreover, I would conduct a class in twenty minutes. Now it was impossible for me to report on my duty in time. Nevertheless, I tried to walk as quickly as possible in an attempt not to be too late. The road was muddy after rain and overhead was the gray cloudy sky. As I turned up at the classroom, I had been ten minutes late for the period while head teacher of the class Ms Lu was taking charge of the students there doing some exercises. I took over the class from her assigning the students to write some English words in the remaining period. In the afternoon when I finished my teaching task, I pumped up the flat tire and cycled home ahead of schedule. In case the pumped air should escape on the way, I carried the pump along. Later when I was to have the tire repaired, I found perplexedly the tire fully inflated. The repairer told me it was the out-of–place valve of the tire that caused flatness of the tire rather than any poke.