It is known that the probability of someone hitting the bull's eye is 0.9. What is the probability of accurately hitting the bull's-eye twice?

0.9*0.9=0.8 1, this question has nothing to do with hitting the bull's-eye four times in a row, because as long as you hit the bull's-eye, the probability is 0.9, just count the times you hit the bull's-eye. Moreover, the principle of classified calculation should be used here, and hitting the bull's-eye twice is the target. The first chance is 0.9, the second chance is 0.9, 0.9*0.9=0.8 1.