问题153: The following two questions are about a four-by-four chess board as follow knight
The following two questions are about a four-by-four chess board as follow knight can be assumed to start from any of the 16 squares on the board.
1) Can the knight visit every square of the chessboard at least once and reach the square where it starts from?
2) Can the knight visit every square of the chessboard exactly once and reach the square where it starts from?
可以直接提问（请注明数学答疑）