There are generally no sample papers or previous year question papers included in the Science textbook for Class 4 students. However, educators and students can find a variety of additional resources online, including websites like EduRev, that provide sample papers, practice questions, and previous year question papers for Science and other subjects. These resources can be beneficial for students to enhance their understanding and prepare for exams.

Here is a breakdown of the answer:

Introduction:
- Science textbooks for Class 4 generally do not include sample papers or previous year question papers.

Availability of Additional Resources:
- Students and educators can find a variety of additional resources online.
- Websites like EduRev provide sample papers, practice questions, and previous year question papers for Science and other subjects.

Benefits of Additional Resources:
- These resources can be beneficial for students to enhance their understanding of Science concepts.
- Sample papers and practice questions help students to familiarize themselves with the exam format and improve their problem-solving skills.
- Previous year question papers give students an idea of the type of questions asked in exams and help them to identify important topics.

Usefulness for Exam Preparation:
- By practicing with sample papers and previous year question papers, students can assess their knowledge and identify areas where they need improvement.
- Solving these papers also helps students to manage their time effectively during exams and increases their confidence.

Conclusion:
- While Science textbooks for Class 4 may not include sample papers or previous year question papers, there are various online resources available, such as EduRev, where students can find these materials to enhance their exam preparation. It is recommended for students to make use of these resources to practice and improve their understanding of Science concepts.