Nuclear fission is a powerful phenomenon that generates energy.

He observed the stars using a sextant for navigation.

We conducted a spectral analysis to investigate the spectral characteristics of this substance.

The Cultural Revolution is a part of China's history.

His father was diagnosed with schizophrenia in the past.

He was diagnosed with schizophrenia.

The meristem of this plant is very active.

Protein-degrading enzymes play a role in breaking down unnecessary proteins in the body.

This problem is difficult.

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