American colleges could see an increase in students unprepared for the demands of college-level work, education experts say.Across the U.S., there are many students like Angel Hope.Hope graduated near the top of his high school class.But on a test ― a University of Wisconsin exam that measures what new students learned in high school ― all he could do was guess.It was like all the problems caused by the pandemic were catching up to him at once.Hundreds of thousands of recent graduates are going to college this autumn after spending more than half their high school years dealing with the pandemic.These students experienced a move to online learning, the difficulties of U.S. teacher shortages, and large changes to their home lives.Many students are believed to be far behind in learning.Allison Wagner is head of All-In Milwaukee - a program that provides financial aid and other assistance to poor students, including Hope.