Chewing gum is illegal.Chewing gum for medical purposes have recently been legalized as part of a U.S trade agreement, although sales are limited to pharmacies. In what Country?

Singapore. (source)

Have they checked the undersides of school desks.

Putting gum under a desk may be a caning offense in Singapore. An American boy got 4 strokes in 1994 for vandalism.

Caning in Singapore

Good answers. Even more details Here.