Nothing. I believe you misspelled WORLD - "on top of the world" means that everything is going well for you and you feel great.
The head person.
The highest amount paid for
if you read the book, i bet you wold find it.
It's not an idiom. It means just what it says -- something is on the crest of a wave. The crest is the top of the wave.
No. It means exactly what it seems to mean - some classes were ranked at the top.
It means that you feel euphoric and totally optimistic.
reach the top
This is not an idiom. The verb "lay" is the past tense of "lie," and means that whatever or whoever the subject of the sentence may be, they were laying down on top of some hay.
It means you are at the peak, the highest point you are going to get. You usually see this in a business sense, as in someone is "on top" of other businesses or people.
It's kind of like "blew his top", which means that he/someone had an outburst of anger.
That means answering with the first thought(s) that come(s) to mind.
No, "blew his top" is considered an idiom.