[填空题]
A bag contains 6 white and 4 orange table ten:pxsuy 0iis83 nis balls. Jack selects a kqdoj mmo26gu98e:-ygzsy;)*uz kb; ball at random from the bagkd8j -2 9zoe6)suyk yu*: m;omzb ;ggq and then, afterwards, John selects a ball at random from the bag.
1. Complete the tree diagram.
2.Find the probability that John chooses a white ball.