Parts of China’s capital closed schools and ordered people tested for the coronavirus on Monday, while European countries opened their borders after a three-month long lockdown. Until last week, Chinese officials had reported no new coronavirus cases in Beijing for nearly two months. But over the past four days, Beijing officials have confirmed 79 cases. The infections were linked to Xinfadi, a market that supplies much of the city’s meat and vegetables. Xinfadi is more than 20 times larger than the seafood market, in the Chinese city of Wuhan, where the coronavirus was first identified. The new cases have led Beijing officials to reestablish strong measures to control the spread of the virus. They include closing schools and sports centers, and requiring body temperature tests at offices, supermarkets, and public spaces.