On days when Xu Sanduo's letters were not received, Wu Liuyi smoked harder than usual. After waiting for them to arrive, he hurriedly read them, folded them, and locked them in a rusty iron box. Xu Sanduo put the letters from Wu Liuyi into the cardboard box where the tank model was originally placed. He read through them many times and repaired the damaged areas with transparent glue.
Conception: