Main Idea 7th grade

There are several ways to determine if a snake is poisonous or not. First, poisonous snakes usually have triangular shaped heads while nonpoisonous snakes have rounded heads. Second, poisonous snakes have pupils that look like slits. Nonpoisonous snakes have pupils that are rounder. Finally, the snouts of poisonous snakes are sometimes upturned, while nonpoisonous snakes have rounded snouts.

What is the main idea of this paragraph?

• The main idea is where snakes live.

• The main idea is how to tell if a snake is poisonous or not.

• The main idea is how poisonous snakes smell.

Elephants use their trunks for many things. Elephants use their trunks to smell. In fact, elephants can smell better than bloodhounds. Baby elephants sometimes suck their trunks to soothe themselves the way human babies suck their thumbs. Elephants do not drink with their trunks. They use their trunks to suck up water and then pour it in their mouths. Elephants also greet each other with their trunks the way humans do by shaking hands. What is the main idea?

• The main idea is how much water elephants drink.

• The main idea is where elephants live.

• The main idea is how elephant use their trunks.

Can you imagine not having a television? Before the 1920’s there were no televisions. The first television set was invented by a 21 year old man named Philo Farnsworth. Farnsworth demonstrated the first moving picture in San Francisco in 1927. Even though it was only a simple, straight line, this was the beginning of electronic television as we know it. What is the main idea?

• The main idea is the invention of television.

• The main idea is hobbies before 1920.

• The main idea is who lives in San Francisco.

George Washington is known as the “Father of Our Country” because of his strong leadership. He was the commander in chief of the Continental Army during the Revolutionary War. After winning the Revolutionary War, George Washington headed the group of men who wrote the Constitution of the United States of America. Later, the colonists elected George Washington as the first president of the United States of America. What is the main idea?

• The main idea is how George Washington led our country.

• The main idea is why the Revolutionary War began.

• The main idea is who wrote the U.S. Constitution.

Did you know that the Statue of Liberty was once brown instead of green? The Statue of Liberty is made of copper, a shiny brown metal. Over time, the Statue of Liberty changed to a pale green color because of a chemical reaction called oxidation. As the statue was exposed to air and water, oxidation occurred. The statue became covered in a thin, green layer. This green layer actually protects the statue from further damage by weather. What is the main idea?

• The main idea is where the Statue of Liberty is located.

• The main idea is how oxidation occurs.

• The main idea is how the Statue of Liberty changed color.

There are several ways to tell the difference between an alligator and a crocodile. Crocodiles are bigger than alligators and have pointed snouts. Alligators have wide snouts. Wild crocodiles are found all over the world, but wild alligators are only found in the United States and China. Another way to tell the difference is to look at their mouths. When a crocodile’s mouth is closed, the fourth tooth sticks out of its mouth. What is the main idea?

• The main idea is where crocodiles live.

• The main idea is differences in crocodiles and alligators.

• The main idea is dangers of crocodiles and alligators.

Animals and plants living in deserts have adaptations which enable them to survive there. Desert plants have little or no leaves where moisture can escape. They also have deep roots to soak up water underground. Many desert animals are nocturnal. They burrow in the soil or sand during the hottest part of the day and are active at night when it is cooler. Desert animals also survive by getting the water they need from desert plants. What is the main idea?

• The main idea how much it rains in the desert.

• The main idea is the types of animals living in deserts.

• The main idea is how animals and plants survive in deserts.

Hand sanitizers can be a good substitute for washing your hands when soap and water are not available. To kill germs, use a hand sanitizer that contains at least 60% alcohol. Pour about a dimesized drop of hand sanitizer on your hands. Then, rub your hands together for 3o seconds to help the hand sanitizer begin its work. What is the main idea?

• The main idea is how to use hand sanitizer.

• The main idea is how germs are spread in hospitals.

• The main idea is where to buy hand sanitizers.

Do you ever wonder what makes gum so chewy? Gum has been around for about 3,000 years. Until the 1940’s, gum was made out of chicle, a type of tree sap. Flavorings were added during the 1860’s to make gum taste better. Now, gum makers use a soft, chewy, and edible type of rubber-like substance to make gum. What is the main idea?

• The main idea is the different flavors of gum.

• The main idea is types of tree sap.

• The main idea is what gum is made of.

Sharks can lose up to 30,000 teeth in their lifetime. Sharks have teeth arranged in rows inside their mouths. These teeth do not have roots like human teeth do, so they fall out easily. When a shark takes a powerful bite into its food, several teeth are lost. When these teeth are lost, new ones push forward from the back rows to replace them. Luckily, sharks continually grow new teeth to replace the thousands they lose. What is the main idea?

• The different way shark teeth look.

• Sharks lose many teeth over their lifetime.

• Sharks are carnivorous predators.