It is not a common expression, but it is sometimes used in organizational behavior (business), sociology or psychology. It refers to the difference between two types of groups: "fixed groups" are those whose members stay together for a long time; "revolving groups" are those with members that only stay together until a specific task is accomplished.
Colin Peters is correct. But I believe a group of snakes is a 'nest' of snakes.
it is not correct English, you rather say still
It is correct.
It would be more correct to say, someone who.
It is correct English to say decent skill but not decent ability
It is correct English to say "He went off on a tangent".
no it is not correct to say you are not for sure instead you can say in proper English that you are not sure about something
No. In English we say "How old are you?"
Yes, it is correct to say out of compliance with. It means out of help with in English grammar.
no you should say "Did you get an A on the English exam?"
Correct is the same as it is in English. It means that it is free from error.
'What a drunkard you are' is a grammatically correct English sentence.