Hiking with some friends provided an opportunity to relax ourselves. Cold with a mixture of sun and snow1a quicker step on the mountain. On the way, we2a large troop of boy scouts and their families heading down as well. The majority of the troop was quickly well ahead and out of3.

    Left behind were a boy and his mother who seemed uneasy. We slowed our4to talk with them before we 5passed them. They caught up again when my friend 6to tie her shoe. The boy at that moment fell down. My friend attempted to 7him as he rolled down the path.

    Helped up, the boy was8, crying in his mother's arms. He said that his knee hurt and I could see the9spreading across the mother's face. I asked if I could help, with my friend explaining that I was a nurse. After a quick 10 I could tell that more than anything he was 11,his mom as well.12he stayed sitting, wrapped in his non's arms. Asking if they needed anything before we continued on, I turned to go leaving the13sitting on a rock.

    I only took a few steps forward before14 that there was more that could be done .I15 to my friends for slowing them down, then turned and asked the boy and his mother if they wanted me to wait and hike down with them when they were 16.I could see the relief wash over the mother's face as she said “yes” and17stood to continue on.

    The New England autumn had left the path 18with beautiful slippery leaves. So we went slowly, ensuring19footsteps. I realized that I was being gifted with more time to take in the20of the woods, conversation with friends and connections.

如图，某几何体的三视图如图所示，则该几何体的各条棱中最长的棱和最短的棱长度之和为（   ）