How long can you hold your breath?

Volume 16 | Gr. 4-8 | U27712
how long can you hold your breath
Materials list
Stopwatch (TB14784) or a clock with a second hand
Tape measure (TB15105)
Graph paper, pad of 50 sheets (9706099)
• Pencil (9728094 or 9727070)
Notebook (TB26495)