1. She sings a song.
2. They arrived at the station.
3. The cat is chasing the mouse.
4. I read a book yesterday.
5. She is studying for her exams.
6. They play football every weekend.
7. The sun rises in the east.
8. He is playing basketball now.
9. She writes a letter every day.
10. They are playing chess.
这些句子都遵循主谓结构的基本形式，即主语（Subject）+ 谓语动词（Predicate Verb）。
