He likes to take a walk in the park at dusk.

Solving problems of arithmetic sequence is difficult.

Understanding geometric sequences is important for understanding mathematics.

The Fibonacci sequence appears in many phenomena in nature.

There is a wonderful exhibition at the museum.

This cell divides to create new cells.

His brother was diagnosed with schizophrenia a long time ago.

He was taken to the hospital because of pulmonary edema.

He experienced failure and had a bitter experience.

He is studying phallicism.