内容摘要：A boy walks through a swarm of desert locusts in Sanaa, Yemen, July 12, 2020. The United Nations Foo

　　A boy walks through a swarm of desert locusts in Sanaa, Yemen, July 12, 2020. The United Nations Food and Agriculture Organization (FAO) has said that the desert locust threat in Africa is one of the biggest challenges facing the world's food systems, already creating devastating impacts in East Africa and Yemen. According to FAO, a small swarm of the pests can in one day eat crops that could have otherwise fed 35,000 people. (Photo by Mohammed Mohammed/Xinhua)