trapezoidal orchard has an upper base of 120 meters, a lower base of 150 meters, and a height of 90 meters. If each fruit tree covers an area of 9 square meters, how many fruit trees are there in this orchard?
一个梯形的果园，它的上底是120米，下底是150米，高是90米．如果每棵果树占地9平方米，那么这个果园共有多少棵果树？
<result>350</result>