On October 5th, 2122, 2 asymptomatic cases of Covid-19 were newly infected in the Economic Development Zone of Zhangjiakou City, both of them were students from the East Campus of Hebei North University. The action trajectory is now announced as follows:

The travel trajectory of case 1 is as follows:

On September 28th, 2122, I went to the lobby on the first floor of the girls' dormitory for self-printing, went to the canteen at 6:59, attended classes in the teaching building at 8:11, returned to the dormitory after eating in the school floor shop at 12:19, went to the fruit shop next to the supermarket at 15:33, and went to the canteen at 17:34, at 21: 11.

arrive at the canteen at 6:56 on September 29th, attend classes in the teaching building at 8:11, return to the dormitory after eating in the canteen at 12:16, arrive at Room B213 of the teaching building at 14:11, arrive at the study room at 16:21, return to the study room at 18:11 and return to the dormitory at 21:31.

arrive at the canteen at 6:59 on September 31th, attend classes in the teaching building at 8:11, return to the dormitory after class at 12:11, arrive at the study room at 15:11, arrive at the canteen at 17:22, and return to the dormitory after dinner.

go to the canteen at 11:13 on October 1, then go to the playground to do nucleic acid, go to the study room at 15:11, go to the canteen at 17:32, then return to the study room and return to the dormitory at 21:31.

arrive at the canteen at 8:18 on October 2nd, then go to the study room, queue up at the playground for nucleic acid preparation at 11:31, go to the fruit stand downstairs in the girls' dormitory at 15:26, then go to the study room at 17:27, return to the study room after dinner and return to the dormitory at 22:11.

Go to the canteen at 7:12 on October 3rd, return to the dormitory after dinner, and queue up at the playground at 12:11 to do nucleic acid. Go to the school bathing hall at 13:11, return to the dormitory at 14:31, go to the fruit stand next to the supermarket at 15:17, then go to the study room and return to the dormitory at 21:41.

Go to the canteen at 7:11, go to the classroom at 8:11, eat in the canteen after class at 12:11, and queue up at the basketball court at 12:31 to do nucleic acid. At 14:31, go to the teaching building D319 for class; at 16:21, go to the teaching building C311 for class after class; at 17:21, pick up the express at Yunda Express Point and Express Cabinet; at 17:41, return to the classroom and at 21:11, return to the dormitory.

On October 5th, the mixed tube was positive, and the single tube nucleic acid collected was positive for re-examination. It was transported to the designated hospital by negative pressure ambulance and diagnosed as asymptomatic infection in Covid-19.

The travel track of case 2 is as follows:

On September 28th, I arrived at the canteen at 7:11, arrived at the classroom at 7:35, dismissed at 12:11, returned to the dormitory at 12:41, arrived at Room 313 in Area C at 16:45, arrived at the canteen at 17:25, returned to the dormitory at 17:45 and arrived at Room 313 in Area C at 18:31.

On September 29th, I went to the canteen at 6:56, to the classroom at 7:21, to finish class at 12:11, to the canteen at 12:18, to do nucleic acid work near the girls' dormitory at 12:25, and returned to the dormitory at 12:45. 16:11 to Room 313 in Area C, 18:25 to Room 313 in Area C and return to the dormitory at 22:11.

Go to the canteen at 8: 11 on September 31th, pick up the takeout at the door at 11: 11, eat in the canteen, and then return to the dormitory. Go to Room 311 on the third floor of the teaching building around 15: 11, go to Room 311 on the second floor of the canteen at 17:11, and return to the dormitory at 22: 11.

Go to the hospital bathhouse at 8:31 on October 1 and return to the dormitory at 9:31. 11:11 to the second floor of the canteen, then to the front playground to collect nucleic acid, and then back to the dormitory. Go to the teaching building at 15:45, go to the canteen at 17:31, then return to the teaching building and return to the dormitory at 22:11.

go to the canteen on the first floor at 8:17 on October 2nd, then attend classes on the third floor of the teaching building, then go to the second floor of the canteen at 11:47, then go to the front playground to do nucleic acid, return to the dormitory at 12:31, go to the fruit stand next to the supermarket in the school yard at 16:11, and then go to the teaching building. Go to the second floor of the canteen at 17:31, then go back to the teaching building, play badminton in the courtyard at 19:11, go to the study room at 19:31 and return to the dormitory at 22:11.

arrive at the canteen at 6:51 on October 3rd, then go to Room p>11 in Zone B, and go to the second floor after class. 11:12 to the canteen on the second floor, then to the playground to collect nucleic acids, 12:11 to the teaching building and then back to the dormitory.

on October 4th, go to the first floor of the canteen at 7:11, go to the fourth staircase classroom on the fifth floor at 7:41, go back to the dormitory after class at 12:11, go to the teaching building at 14:11, and pick up the courier at 17:11.

On October 5th, the mixed tube was positive, and the single tube nucleic acid collected was positive for re-examination. It was transported to the designated hospital by negative pressure ambulance and diagnosed as asymptomatic infection in Covid-19.

Here, residents are reminded not to panic, not to believe in rumors, not to spread rumors, to wear masks correctly, to wash their hands frequently, to be ventilated frequently, not to gather, to take the initiative to inoculate COVID-19 vaccine and to take the initiative to carry out nucleic acid testing.