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.

He was diagnosed with bipolar disorder.

This software has forward compatibility.

This software maintains backward compatibility.

He was diagnosed with congestive heart failure.

The success of this project is influenced by a lot of uncertainty.