What has many keys, but can't open a single door?
The more you take, the more you leave behind. What am I?
When you need me, you throw me away. When you're done with me, you take me back. What am I?
Before Mount Everest was discovered, what was the highest mountain on Earth?
Always in you, sometimes on you. If I sorround you, I can kill you. What am I?
You have heard me before, though you hear me again. Then I die until you call me again. What am I?