2 . Beside pencil sharpeners and calendars in classrooms throughout Minnesota’s Lakeville Area Schools, there are now big blue boxes with a red button and the word POLICE. The button sends a text message to emergency correspondents, alerts the rest of the school to potential danger, and _______ 1,200 pounds of magnetic (磁性的) force to keep the door shut.

It’s one of the measures that Michael Baumann has employed to _______ the schools in his district and protect against active shooters since he became supervisor in 2017. He hired four more advisers to improve mental-health services. He established a team to monitor _______ threats of violence. He spent $14.4 million installing the emergency-alert system and building panels into walls that are designed to stop bullets—all _______ helping students and teachers survive an active shooter.

“Everybody goes to bed and thinks, ‘That’ll never happen in my school district. ‘ Well, I can tell you as a supervisor, that’s the _______ dream,” says Baumann, who previously served in the Army. “I felt like it was my _______ to do what I could.”

Fear of shootings has turned school security into a _______ industry. The market for school-security equipment and services reached $2.7 billion in 2017, according to a report by the research firm Omdia. That was before the 2018 shooting at Marjory Stoneman Douglas High School in Parkland, Fla., further increased the focus on security measures at schools.

The school shooting in Uvalde, Texas, on May 24 this year has restarted the discussion about whether safety measures at schools can _______ mass shootings. And many politicians, after indicating that they are _______ to support gun-safety lawmaking, have argued instead that heightened physical security measures are necessary to prevent future attacks.

________ , experts say it’s not clear that such measures actually make schools safer. Research shows that the number of deadly shootings at schools has increased since 2012, during a period in which protective measures also ________ . There also isn’t clear evidence that school resource officers (SROs) improve safety. SROs were ________ in Uvalde and in Parkland before the gunmen entered the schools, but failed to stop those shootings.

“When we add metal detectors, observation cameras, increased police presence, active-shooter drills, and we turn schools into this mix of castles and ________ ,” says Bryan Warnick, an education professor at Ohio State University.

Although many school districts invest in security in the hopes of preventing shootings, some worry that reinforcing schools ultimately makes ________ responsible for solving the gun-violence outbreak.

“Schools are ________ with trainings and new procedures,” Warnick says. “It’s a larger social problem of easy access to guns, of lack of access to mental-health care.”