By KEN MORITSUGU
BEIJING (AP) — The city of Shanghai is doubling down on pandemic restrictions after a brief period of loosening up, frustrating residents who were hoping a more than monthlong lockdown was finally easing as the number of new cases falls in China’s largest city. Teams in white protective suits have begun entering the homes of coronavirus-infected people to spray disinfectant. Shanghai has also ordered people in some areas to stay in their homes again after letting them out for limited shopping in recent weeks. China’s adherence to a “zero-COVID” strategy, as many other countries loosen restrictions and try to live with the virus, is exacting a growing economic and human cost.