My sick father is seen by a doctor every day.

The Black Death struck Europe in the 14th century, taking many lives.

A stray cat is playing in my garden.

There is a wonderful exhibition at the museum.

The Fibonacci sequence appears in many phenomena in nature.

This cell divides to create new cells.

Solving problems of arithmetic sequence is difficult.

Understanding geometric sequences is important for understanding mathematics.

He was diagnosed with leukemia.

He is suffering from the ouch-ouch disease.