What is the shape of one side of the dice in flying chess?

Analysis: The sum of every two opposite sides of the flying chess dice is 7, so the opposite of 4 is 3, the opposite of 5 is 2, and the opposite of 1 is 6. Judging from these three pictures, the bottom of the third picture is 1, so "?" The number of faces is 6. As can be seen from the figure, the antonym of 4 is 3, the antonym of 5 is 2 1, and the antonym of 6 is. From the first picture to the third picture, we can see that the bottom of the third picture is 1, so "?" The number of faces is 6. Therefore, D. Comments: This question mainly examines the spatial figure of the cube, and analyzes and answers questions from the opposite side.