1) The construction of the Great Wall of China began in the 7th century BC and was completed over several centuries, spanning thousands of miles.

2) The eye of a cyclone is a region of calm, relatively clear skies and light winds at the center of the storm.

3) The sport of golf originated in Scotland and is played on courses with 18 holes, each with a designated par score.

4) The ocean covers about 71% of the Earth's surface and contains roughly 97% of the planet's water.