On a sunny afternoon, Mi Xiaoquan and his friends were busy in the laboratory.They were trying to make a rustic telephone, a simple voice-transmitting device.This experiment seems simple, but it is full of unknowns and surprises.

After a lot of hard work, the native phone was unexpectedly successful.When Mi Xiaoquan whispered softly on the other end of the phone, Jiang Xiaoya in the distance could hear his voice clearly.Tietou was also very excited. They were proud of this gadget they invented.The mystery of all this is due to the vibration generated by sound waves, which transmits the sound.Chechi explained this principle to everyone, which is the mechanical vibration transmission of sound waves.

However, just as they were cheering for success, Mi Xiaoxuan wanted to try the experiment again, but was unexpectedly interrupted by Li Li.As the monitor, Li Li urged Mi Xiaoxuan to go to class.Mi Xiaoquan was in a bad mood and couldn't help complaining to Jiang Xiaoya about the monitor into the phone.Unexpectedly, Li Li could also hear these contents through the phone.As a result, Mi Xiaoquan was written down in the notebook by the monitor.

Li Li criticized Mi Xiaoquan in front of the whole class in the name of the teacher.After that, every little move of Mi Xiaoquan and his friends was discovered by the squad leader in time.They felt that there must be a hidden clue in the class, so they decided to find this mysterious supervisor.

After some investigation, their suspects included Hao Jing, Zhou Ran and Xu Doudou.But after a series of observations and trials, they found that these people were not supervisors.In the process, Mi Xiaoquan misunderstood that his friend Tietou was too close to the squad leader, which almost destroyed their friendship.

Eventually, they discovered that the squad leader had not set up a hidden line, but was eavesdropping on their conversations through the phone.After learning the truth, the relationship between the Iron Triangle was repaired, and Li Li realized that his behavior was too extreme and apologized to the whole class.