Pains and Sickness
Headaches can be very painful and can last for a long time.
If you have a headache, your head hurts.
A sprained ankle can be so painful that you can't walk.
Someone with a sprained ankle may need to use crutches to walk.
If you have a sore throat, it may be painful to swallow.
A sore throat can be caused by viruses or bacteria.
A burn is an injury to the skin caused by fire or heat.
If you get too close to a fire, you will be burnt.
An earache is a sharp, dull or burning pain in the ear.
Common causes of an earache include an infection, a changing air pressure or water in the ear.
When you have a sore throat, the back of your throat is often red and infected.
Earaches occur more often among small children than adults.
A headache can be caused by an injury to the head.
Landforms
Mountains are landforms higher than 2,000 feet or about 600 meters above sea level.
Hills are like mountains, but not as tall.
Mountains are formed by forces deep within the Earth and are made of many types of rocks.
Rivers are streams of water that usually begin at mountains and flow into the sea.
Many early cities were built alongside rivers.
Most of the world's water is in the oceans, which are large bodies of salt water.
The oceans are also an important source of oxygen.
Desserts are areas of land that receive little or no rainfall.
The amount of rainfall in some deserts is so low that only a few plants can survive.
A valley is a low, relatively flat area between hills or mountains, often with a river running through it.
Some valleys are formed by flowing water, and others are formed by glaciers.