Suddenly, a smile floated around his mouth, because he saw the right side of the train, beside a tall poplar tree, several small trees were growing up against the wind and sand.
Dad's smile disappeared and his face became serious. He thought for a moment and said to his son and little daughter, "Poplar trees have always been so straight. Where it is needed, it will quickly take root and sprout and grow thick branches. No matter whether it encounters wind, rain, snow, drought or flood, it is always so straight, so strong, not weak and unshakable. " There are some profound sentences in the article, such as "beside a tall poplar, several small trees are growing against the wind and sand." Find them, understand them carefully, and then write them down.