【Question 9】Nine beauties, some are always sincere and tell the truth as angels, the rest are always flattering and tell lies as devils. The first beauty says: “There is exactly 1 devil among us”; the second beauty says: “There are exactly 2 angels among us”; the third beauty says: “There are exactly 3 devils among us”; the fourth beauty says: “There are exactly 4 angels among us”; the fifth beauty says: “There are exactly 5 devils among us”; the sixth beauty says: “There are exactly 6 angels among us”; the seventh beauty says: “There are exactly 7 devils among us”; the eighth beauty says: “There are exactly 8 angels among us”; the ninth beauty says: “There are exactly 9 devils among us”; There are exactly $\qquad$ angels among these beauties.
Analysis:
"Among us, there is exactly 1 devil," "Among us, there are exactly 3 devils," "Among us, there are exactly 5 devils," "Among us, there are exactly 7 devils," "Among us, there are exactly 9 devils" — among these 5 statements, at most 1 can be true; similarly, "Among us, there are exactly 2 angels," "Among us, there are exactly 4 angels," "Among us, there are exactly 6 angels," "Among us, there are exactly 8 angels" — among these 5 statements, at most 1 can be true, so there can be at most 2 angels. Therefore, the number of angels is either 1 or 2.
Assuming there is exactly 1 angel, this would mean there are 8 devils. In this case, we can determine that all 9 statements made by the beauties are false, which is a contradiction. Assuming there are exactly 2 angels, this would mean there are 7 devils. In this case, we can see that the second and seventh beauties are telling the truth, while the others are lying, which is consistent.
Therefore, among these beauties, there are exactly 2 angels.