根据所给提示，完成句子。每空一词，含缩略词。
1. They are girls.(改为单数句)
_______ _______a girl.
2. I am Mary Green.(改为同义句)
________ ________Mary Green.
3. He's my teacher.(改为一般疑问句)
________he ________teacher?
4. His cousin has a dictionary.(改为否定句)
His cousin ________ ________a dictionary.
5. Do you have a Music Festival at school,boys and girls?(做肯定回答)
________ , _______ _______.
6. The book is ten yuan.(对划线部分提问)
________ ________is the book?
7. I can see some keys on the dresser.(对划线部分提问)
________can you_______on the dresser?
8. She has a black watch.(变为复数句)
They _______black ________.
9. What's her age?(改写同义句)
________ _________is she?
10. 你需要运动包吗?(完成译句)
Do you need bags_________ __________?
11. 让我们去那家书店看看吧!(完成译句)
Let's go and have a ________ _________that book store.
12. 他经常和他父亲一起去看京剧。（完成译句）
He_________goes to see Beijing Opera ________his father.
溶液中含有0.2nA个NO3-