Hi Angki,
Hope you are doing well. Solving sample papers before any exam will help you immensely with your preparation. Also, do analyze your mistakes and shortcomings if any and make proper strategies to overcome them on the final day.
The sample paper of biology for CBSE 2021 can be found in the following link:
https://school.careers360.com/download/sample-papers/cbse-12th-class-biology-solved-sample-paper-2021
If you need sample papers of any other subjects for CBSE, visit:
https://school.careers360.com/articles/cbse-class-12-sample-papers
Hope this helps.
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