A reader is seen at the San Francisco Public Library in San Francisco, the United States, May 3, 2021. The San Francisco Public Library began to reopen for limited indoor service on Monday. (Photo by Li Jianguo/Xinhua)
A reader is seen at the San Francisco Public Library in San Francisco, the United States, May 3, 2021. The San Francisco Public Library began to reopen for limited indoor service on Monday. (Photo by Li Jianguo/Xinhua)
A staff member works at the San Francisco Public Library in San Francisco, the United States, May 3, 2021. The San Francisco Public Library began to reopen for limited indoor service on Monday. (Photo by Li Jianguo/Xinhua)
A notice board reminding people of epidemic prevention measures is seen at the San Francisco Public Library in San Francisco, the United States, May 3, 2021. The San Francisco Public Library began to reopen for limited indoor service on Monday. (Photo by Li Jianguo/Xinhua)