Read the passage.
To Stand or Not to Stand?
In 2016, Vallecito Elementary School in San Rafael, California, became the first U.S. school to replace all of its ordinary desks with raised desks that students stand at. Speaking to a reporter from TIME for Kids magazine, one student at the school gave the standing desks high praise. "You feel happier, you're less tired, and you're more active," she said. According to several studies, children working at standing desks burn more calories and are more focused on tasks. However, some teachers and parents are opposed to the change. They are concerned that standing for long periods of time could cause fatigue, the strain on the legs and feet, or posture problems. In addition, standing desks are more expensive than seated desks. Only time will tell whether standing desks will prove to be the next big trend or a failed experiment.

What is the main idea of the passage?

Studies have shown that standing desks help students focus on their schoolwork while being more active.
Some people say that standing desks promote good study habits, but others are wary about the new decks.