She is screaming because she is really scared. Something is chasing her, so she is screaming for help.
她在尖叫，因为她真的害怕。有东西在追她，所以她发出尖叫声求救。
He's shouting because he is angry. When he's really angry, he often shouts like this.
他在大喊大叫，因为他很生气。当他真的生气时，他经常这样。
She's sleeping because she's tired. Last night she didn’t get enough sleep, so today she has no energy.
她在睡觉，因为她累了。昨晚她没有睡好，所以今天没有精神。
She’s crying because she’s sad. She got some bad news a few minutes ago.
她在哭，因为她很伤心。几分钟前她知道了一些坏消息。
She’s smiling because she’s happy. Her boyfriend just called and he is returning from a long trip.
她在笑，因为她很开心。她男朋友刚给她打电话，长途旅行后他正在回家途中。
