Airbnb says it lost nearly $1.2 billion in the first quarter, about three times as much as it lost a year ago, as travel remains depressed because of the pandemic. But Airbnb’s revenue was not only better than a year ago, it was higher than it was during the first quarter of 2019, before the pandemic. The company is telling shareholders that it expects a travel rebound unlike any other. Still, Airbnb is expressing concern about travel restrictions and lockdowns in Europe, a key market for summer rentals. And the company says it’s too early to tell whether the pace of the travel recovery will continue in the second half of the year.