Š¿Žšƒ‚ƒoƒCƒ‹ƒQ[ƒ€
Žc”O
period of time =
1. Šú
2. “s
3. •M
4. “s

ƒŒƒxƒ‹3. •ÏX
SDAL“‡‰pŒêŠwZ