Choose the most reasonable measure by underlining it.
1. length of a pencil (19mm, 19cm, 9dm)
2. height of a child (12cm, 12dm, 12m)
3. height of a mountain (2000mm, 2000m, 2000dm)
4. length of cloth for a skirt (1m, 1mm, 1km)
5. distance from the earth to the moon (384,400m, 384,400km, 384,400dm)​