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 tongue of a blue whale is so big that about 50 people could stand on it.

3) The NBA (National Basketball Association) is widely regarded as one of the most popular and competitive professional basketball leagues in the world.

4) The Grand Canyon, located in Arizona, United States, is a massive and awe-inspiring natural formation carved by the Colorado River. It is approximately 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and reaches a depth of over 1.8 kilometers (1.1 miles).