课文整体梳理。
这是一篇简短易懂的课文，讲述了树和喜鹊从孤单到____的过程。让学生知道，只有保护____，多____，才能改善我们人类生存的环境。
Mary's grandpa is always ______ in the mountain village. He tells her he feels very______. So she's going to visit him next week.
