A doctor is someone who makes sick or injured people better. Their main role is to find out what is wrong with someone and prescribe treatment, while a nurse's role is mainly to look after sick or injured people as they get better. Some doctors perform surgery, cutting people open to fix what is wrong inside, to help people get better.
Scientific name: canis lupus familiaris
People have been keeping dogs as pets for thousands of years. Dogs can be used to herd animals like sheep, and if they are well trained they will obey commands like sit and fetch.
Dogs come in a huge variety of different colours and sizes, from tiny Chihuahuas right up to huge dogs like the Great Dane. A female dog is called a bitch and a baby dog is called a puppy. Modern dogs were domesticated from wolves, and were originally kept as hunting companions.
A dome is a shape that is half a sphere. One side of a dome is flat, and is the shape of a circle. If you turn a salad bowl upside down it is dome shaped. A dome made out of shapes that doesn't have a smooth surface is a geodesic dome.
Something is domestic if it relates to house and home. An animal is domestic if it is tame or has been bred to serve people somehow.
The opposite of domestic is industrial. The opposite of tame is wild.