People point to photos of Doolittle raiders exhibited in the World War II Gallery of the National Museum of the U.S. Air Force in Dayton, Ohio, the United States, on July 24, 2019. Four months after the Japanese attack on Pearl Harbor, a group of 80 U.S. airmen named after their mission commander Jimmy Doolittle volunteered to retaliate. Most of them were later rescued by voluntary Chinese civilians and troops. Recent researches from the U.S. side have estimated that up to 250,000 Chinese people lost their lives because they helped Doolittle Raiders. The National Museum of the U.S. Air Force displays more than 360 aircrafts and thousands of historical items that bring history to life. In its World War II Gallery, many exhibits reveal a memorable part of China-U.S. cooperation when the two countries joined hands in fighting fascism and safeguarding world peace. (Xinhua/Zhang Fengguo)