Main Idea

Before toothbrushes were invented, people used natural objects to clean their teeth. People cleaned their teeth with small twigs. The first toothbrushes were made from bones and bristles from boars, horse hairs, or even feathers. Today the bristles on most toothbrushes are made from nylon.

• People used to clean their teeth with twigs.

• Most toothbrushes are made from nylon.

• Before toothbrushes were invented, people used natural objects to clean their teeth.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RL.2.2

Beavers make dramatic changes to the environment. When beavers build a dam across a river, they create a pond or even a lake. Land that was once dry gets covered in water. The new lake becomes a home for birds, fish, and other kinds or wildlife.

• Beavers make dramatic changes to the environment.

• Beavers create new ponds and lakes.

• Beavers build dams across rivers.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RI.2.2

Christopher Paolini became an author at a young age. He was just 15 years old when he wrote the first draft to the fantasy book Eragon. His parents helped him to self-publish and to promote the book in schools and libraries. Three years later, Knopf Books for Young readers asked Christopher's family if they could publish the book. Today, Eragon is a best seller.

• Christopher Paolini wrote Eragon.

• Christopher Paolini became an author at a young age.

• Eragon was published by Knopf Books for Young Readers.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RL.2.2

A mother octopus takes good care of her eggs. She lays thousands of eggs in a den. Once the eggs are laid she guards them constantly and does not leave the den. When the eggs hatch, the tiny baby octopuses float away. The the mother dies.

• A mother octopus takes good care of her eggs.

• A mother octopus does not leave the den.

• A mother octopus lays thousands of eggs.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.3.1

CCSS.RL.4.1

The lives of the Maasai people in East Africa are centered around their cattle. They depend on the cattle for their food. They sell cattle to the outsiders to pay for the things that they need. They spend most of their time tending to their cows.

• The lives of the Maasai people are centerd around their cattle.

• The Maasai spend most of their time tending their cattle.

• The Maasai people live in East Africa.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.3.1

CCSS.RL.4.1

In Peru, many people eat Guinea pigs. Guinea pigs are a good source of protein and are easy to raise. They can also provide a much needed source of income for people who raise them to sell.

• Guinea pigs are a good source of protein.

• Guinea pigs are cute and fluffy.

• In Peru, many people eat Guinea pigs.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.3.1

CCSS.RL.4.1

In Australia, cattle and sheep are raised on huge ranches called stations. A station may be so large that low-flying helicopters are used to herd the animals. You could drive for several days in one direction and never leave the station.

• Helicopters are used to herd animals in Australia.

• In Australia, cattle and sheep are raised in huge ranches called stations.

• There are a lot of cattle in Australia.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RL.2.2

Sharks have a lot of teeth. A shark may have up to 3,000 teeth at one time. Shark teeth grow in rows. When a shark loses a tooth, it is replaced by a new tooth from the row behind it. A shark may have over 20,000 teeth over the course of its life.

• Sharks have a lot of teeth.

• Shark teeth grow in rows.

• A shark may have up to 3,000 teeth.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.3.1

CCSS.RL.4.1

Most animals do not recognize themselves in a mirror. They think that the reflection is another animal. Some animals that do recognize themselves are elephants, dolphins, chimps and great apes.

• A dolphin can recognize itself in a mirror.

• Most animals do not like to look in mirrors.

• Most animals do not recognize themselves in a mirror.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RI.2.2

The smallest monkey in the world is the pygmy marmoset. A pygmy marmoset is only about 5 inches (13 cm) tall and weighs just 4 ounces. Pygmy marmosets live in the Amazon rain forest in South America.

• A pygmy marmoset in about 5 inches tall.

• Pygmy marmosets live in the Amazon.

• The smallest money in the world in a pygmy marmoset.

Tags

CCSS.RI.3.2

CCSS.RI.4.2

CCSS.RL.3.2

CCSS.RL.4.2

CCSS.RI.5.2