Fill in the gaps with the missing words

Once astronauts will fly to Mars to meet aliens. There are several types of aliens which can live on the red planet.

Blue aliens are the cleverest. They have three [ ] and four [ ]. They have two small [ ] to hear over long distances. Who knows, maybe they can listen to our speech on Earth too.

Red monsters are very friendly. They have only one big [ ], one [ ], two [ ] and two [ ]. They are good at cooking mushrooms and riding bikes.

Purple monsters live at the bottom of the mountains near the river. Their red [ ] helps them to hide in flowers. They have one big eye in the central part of the [ ] and two small eyes, one on each side. They can easily look for food to eat. They also find minerals to build shiny houses. Their big fluffy ears help them to fly to other planets.