once

The film is a timeless classic that everyone should see at least once.

The film is a timeless classic that everyone should see at least once.

The fish tank needs to be cleaned once a week.

The fish tank needs to be cleaned once a week.

The Earth spins on its axis once every twenty-four hours.

The Earth spins on its axis once every twenty-four hours.

Most people are immune to chickenpox after having it once.

Most people are immune to chickenpox after having it once.

The Earth rotates on its axis once every twenty-four hours.

The Earth rotates on its axis once every twenty-four hours.

The museum's board of trustees meets once a month.

The museum's board of trustees meets once a month.

The ancient cave was once a temporary dwelling for nomadic tribes.

The ancient cave was once a temporary dwelling for nomadic tribes.

Scientists theorize that the planet was once covered in water.

Scientists theorize that the planet was once covered in water.

The small village was once a remarkably homogeneous community.

The small village was once a remarkably homogeneous community.