I wouldn't be caught dead in sleeping during the class.
The idiom is "dead certainty". It means it's in the bag = this is a dead certainty = this is cinch
It is actually an idiom.
This is not an idiom. Idioms make little or no sense unless you know the definition. This sentence makes perfect sense, so it is not an idiom. The dead fish smelled so bad that even as high as Heaven, you could smell them.
All objects which have mass have a centre of gravity.
The opening line of the book, "Old Marley was dead as a doornail." Dead as a doornail is an idiom.
If by "donut" you mean hentai, then yes.
Things tend to be quiet at night, as if they were "dead." So if something is "dead as night," it means it is very quiet, not moving around, not making noise.
Nothing
They are implying that they have "killed" you - you are in big trouble with them, and they are going to make you pay for whatever you just did to them.
donut in tennis means u have a score of 0 in a set this is reffered to as a donut
The idiom "they froze in their tracks" means that they stopped what they were doing. Example- The robbers froze in their tracks when they heard the alarm.