Here is the story.
　　Now the children are at school. Amy is sewing. She is practicing. She is sitting on a bench. She is sitting near Timmy.
　　Timmy is at school too. Timmy is studying. He is sitting behind his desk. He wishes he could play with the other children.
　　John and Susan are also at school. They are playing outside. They are picking flowers for their teacher. John is carrying his hat. Susan is wearing a bonnet （童帽）.
　　At this moment, Sarah is walking by the door. She is helping the teacher. She is carrying textbooks to the shelf.
　　Exercises:
　　A. 用现在进行时回答下列问题：
　　1. Where is Amy sitting now? What is she doing?
　　____________________________________
　　2. Where are John and Susan playing? What is Susan wearing?
　　____________________________________
　　3. At this moment, where is Sarah? Why is she carrying textbooks?
　　____________________________________
　　B. 用否定句、一般疑问句、特殊疑问句和反义疑问句改写下列句子：
　　Examples for the sentence “Billy is writing a letter.”
　　Negative: Billy is not writing a letter.
　　Yes/No Question: Is Billy writing a letter?
　　WH-Question: What is Billy doing?
　　Tag Question: Billy is writing a letter, isn’t he?
　　1. He is sitting behind his desk.
　　Negative: ____________________________
　　Yes/No Question: _____________________
　　WH-Question: _______________________
　　Tag Question: ________________________
　　2. John is carrying his hat.
　　Negative: ____________________________
　　Yes/No Question: _____________________
　　WH-Question: _______________________
　　Tag Question: ________________________
　　用法：
　　1. Actions that are happening now （现在正在进行的动作）
　　2. Actions that are currently in progress （当前一段时间或现阶段正在进行的动作）
　　3. Planned future actions （有计划将要发生的动作）