What does the below rebus riddle means?

How is the moon similar to a dollar?

who is silent in the parliament?

Before Mount Everest was discovered, what was the highest mountain in the world?

Which wheel of car does not rotate when you turn your car right?

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

What Deficiency does the below rebus represent?

VIT_MIN

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?