1. Tax- a compulsory contribution to state revenue, levied by the government on workers' income and business profits, or added to the cost of some goods, services, and transactions.
2. Echo- a sound or series of sounds caused by the reflection of sound waves from a surface back to the listener.
3. Glass- a hard, brittle substance, typically transparent or translucent, made by fusing sand with soda, lime, and sometimes other ingredients and cooling rapidly. It is used to make windows, drinking containers, and other articles.
4. Pencil- an instrument for writing or drawing, consisting of a thin stick of graphite or a similar substance enclosed in a long thin piece of wood or fixed in a metal or plastic case.
