Stamps are what travel around the worldstaying in one spot. Slippers and walking stick can also travel around the world but they will not stay at one spot. So they are eliminated.
It is an investment strategy that involves the buying of money market instruments or currencies in anticipation of a price rise or a future increase in demand. Buying forward allows an investor to take advantage of future and potential profits by buying now at alower price, and selling when prices rise.
Packet filter is a standard router equipped with some extra functionality. The extra functionality allows every incoming or outgoing packet to be inspected. Packets meeting some criterion are forwarded normally. Those that fail the test are dropped