We consider the following $10-$bit message: $0011111111.1)$ We add to this message a CRC calculated by the generator polynomial x$2+$x$.$ What is the coded message $?2)$ The coded message is preceded and followed by a flag. It is transmitted according to the principle of binary transparency $($bit stuffing$).$ What is the transmitted frame? $3)$ During transmission, bits $16$ and $17$ of the frame $($the first bit being numbered $1)$ are changed into their opposites. What is the frame received? What is the diagnostic result? receiver level? $4)$ Give an example of errors that can affect the sent frame without the receiver can detect them. Justify your answer.