Good Riddles

Question: Harry, the happy hippo, happily hopped from the hippo hospital. How many h's are in this sentence?

Question: I'm the one that gives you information, I'm the one that lets you have the ability to control yourself, I'm the one that stores all memories and without me you'll be dead in a instant. What am I?

Question: What is tall and have 4 legs

Question: You were asked to label the light switches for your company. You are in a room, with unlabeled light switches. There are 3 of them, and there are 3 lightbulbs in the next room. You can not travel back and forth. How do you successfully label the lightbulbs???

Question: what is ready when you add a letter inside?