1) The Great Lakes, consisting of Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, form the largest group of freshwater lakes on Earth by total area. They are shared by the United States and Canada and are of significant ecological and economic importance.

2) A newborn kangaroo is about 1 inch (2.5 centimeters) long and weighs less than a gram.

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

4) The fastest recorded serve in tennis was achieved by Sam Groth at 163.7 miles per hour (263.4 kilometers per hour) during a tournament in 2012.