Meaning: This sentence describes an action being performed by a boy, indicating that he is currently moving quickly on foot within a park.
Choice of Words: **Boy**: A male child. **Is**: Present tense of the verb 'to be', indicating a state of existence or occurrence. **Running**: Present participle of the verb 'to run', indicating a fast movement on foot. **In**: A preposition indicating a location or position within something. **Park**: A public area with trees, grass, and often playgrounds and other recreational facilities.