District 1 of Huangzhuang apartment isolation site in Shijiazhuang, north China's Hebei Province, entered the final stage of construction on Monday, soon to be put into use for contacts in isolation for medical observation against COVID-19. At the A01 Unit in District 1 of the isolation center, basic infrastructure and lightning construction were completed, while part of the installation of air conditioner and water heater was still underway.