Continuity is the key to success.

When I happened to pass by the library, I ran into an old friend by chance.

We should always remember the power of Kannon in difficult times.

Einstein proposed the theory of relativity.

His actions always have a duality.

My younger brother caught the influenza.

This material has high corrosion resistance.

The prevention of venereal diseases is most important in safe sexual behavior.

This equation has homogeneity.

Radioactive elements are produced in nature and scientific experiments.