The cold door comes from Ling Xuan's "Book of Jin" Volume 4 Liu Yichuan: "The top grade has no cold door, and the bottom grade has no potential home." Interpretation: In this way, high-level officials have no talents from lower levels, and low-level officials have no people from rich and powerful families.
Sentence: Although he comes from a poor family, his father will support him to go to school with the money he earned from hard work. Their stories are shocking and make students from poor families hold their heads high.