题目

I look around and can’t recognize where I am. It seems familiar but distant. I see my friends gathered by a stage where music is playing and I run over. As I begin running towards them, they become further and further away. I keep calling for them, but no one hears me. I start hearing a distant alarm-like sound and I am transported away. I woke up in a daze (茫然) sitting in my bed.“Oh, it was only a dream,” I said to myself. I have always had vivid and intense dreams. Sometimes, it feels like I haven’t even slept because I have been living out my dreams during my sleep.Today, dreami某元素原子的质量数为A，它的阴离子Xn-核外有x个电子，w克这种元素的原子核内中子数为