PROVIDENCE, R.I. (AP) — When the new coronavirus surfaced at Saint Raphael Academy after a school group returned from a trip to Italy, officials decided to close the Rhode Island Catholic high school for two weeks.

Instead of cancelling classes, the school in Pawtucket instituted "virtual days" where students are expected to work from home, check for assignments through an online portal and occasionally chat with teachers.

A few miles away, a public charter school also closed after a teacher who attended the same Italy trip awaited test results. But at Achievement First, the two days off were...