Good Riddles

Question: Change a long pause into a short one by doubling a letter.What are the words?

Question: Why does the second shape have an open block when the first shape does not?

Question: When you fall in me your as happy as could be, but you fall into depression when you lose me.

What am I?

Question: How many people do you need to have the odds be in favor (at least 50% chance) of two people having the same birthday?

Question: I am a digit, but two of the ten.
Two of me make a promise.

What am I?