Every April I am troubled by the same concern -- that spring might not occur this year. The landscape looks dull, with hills, sky and forest appearing gray. My spirits ebb, as they did during an April snowfall when I first came to Maine 15 years ago. "Just wait," a neighbor advised. "You'll wake up one morning and spring will just be here."  And look, on May 3 that year I awoke to a green so amazing as to be almost electric, as if spring were simply a matter of flipping a switch. Hills, sky and forest revealed their purples, blues and green. Leaves had unfolded and daffodils were fighting their way heavenward.  Then there was the old apple tree. It sits on an undeveloped lot in my neighborhood. It belongs to no one and therefore to everyone. The tree's dark twisted branches stretch out in unpruned  abandon. Each spring it blossoms so freely that the air becomes filled with the scent of apple.  Until last year, I thought I was the only one aware of this tree. And then one day, in a bit of spring madness, I set out with pruner to remove a few disorderly branches. No sooner had I arrived under the tree than neighbors opened their windows and stepped onto their porches. These were people I barely knew and seldom spoke to, but it was as if I had come uninvited into their personal gardens.  My mobile-home neighbor was the first to speak."You're not cutting it down, are you?" she asked anxiously. Another neighbor frowned as I cut off a branch. "Don't kill it, now," he warned. Soon half the neighborhood had joined me under the apple tree. It struck me that I had lived there for five years and only now was learning these people's names, what they did for a living and how they passed the winter. It was as if the old apple tree was gathering us under its branches for the purpose of both acquaintanceship and shared wonder. I couldn't help recalling Robert Frost's words:  The trees that have it in their pent-up buds   To darken nature and be summer woods   One thaw led to another. Just the other day I saw one of my neighbors at the local store. He remarked how this recent winter had been especially long and complained of not having seen or spoken at length to anyone in our neighborhood. And then, he looked at me and said, "We need to prune that apple tree again." In Para. 4, "neighbors opened their windows and stepped onto their porches" probably because   _  .
they were surprised that someone unknown was pruning the tree they wanted to prevent the author from pruning the tree they were concerned about the safety of the tree they wanted to get to know the author