I often go to the cinema on weekends.

Life is a series of ups and downs.

Life is a series of vicissitudes.

The artificial satellite is orbiting around the earth.

The study of nekton is an important part of marine biology.

In organic chemistry, we use the Newman projection to represent the three-dimensional structure of molecules.

The Fischer projection is a commonly used representation method in organic chemistry.

In organic chemistry, we use the Haworth projection to represent the three-dimensional structure of sugars.

In the organic chemistry class, there was an explanation of the Natta projection.

He became obsessed with publicly-owned gambling enterprises and used up all his savings.