奥巴马每周电视讲话:总统呼吁维护世界和平与安全 远离核恐怖主义 Hi, everybody. This week, I'm speaking to you from our Nuclear Security Summit. I welcomed more than 50 leaders from around the world to make sure we're working together to meet one of the gre 英语演讲 2020-08-20 hisen
