We are ____ up the Christmas tree, now. [ ]
A. put
B. to put
C. putting
答案：C
水果店一天卖出苹果45箱，卖出桔子的箱数比苹果多8箱，卖出的橙子是苹果和桔子的总数的3倍．卖出橙子多少箱？
如图所示，请画出撬图钉时的动力臂和阻力臂．
