The International System of Units is the standard measurement system used by scientists all over the world.

I felt his behavior was very free.

He and I are related by blood.

There is a complex love triangle between them.

It's difficult to calculate the area of this hexagon.

Please calculate the area of this right-angled triangle.

The signal from the cell phone relay-station in this area is weak.

I analyze data using a spreadsheet software.

Roundworms are an important part of the soil and contribute greatly to the health and fertility of the soil.

The characteristic of annelids is that their bodies are divided into ring-shaped segments.