Competition, cooperation needed in energy development, environment protection: U.S. energy secretary

U.S. Energy Secretary Rick Perry delivers a speech at CERAWeek in Houston, Texas, the United States, on March 13, 2019. The 38th CERAWeek, which kicked off on Monday, is an annual energy meeting held by the London-based information company IHS Markit with the attendance of prominent speakers from energy, technology and financial sectors. This year's meeting was attended by more than 4,500 guests from over 70 countries and regions. (Xinhua/Liu Liwei)