Mars is our neighboring planet and has some interesting similarities to Earth. Mars, also known as the Red Planet, is a rocky planet with an active atmosphere. Mars has seasons, ice caps, and landforms, such as volcanoes and canyons. Scientists have proven that Mars has experienced ancient flooding. One day on Mars lasts 24.6 hours, which is very similar to Earth. With all these similarities to our home planet, scientists often wonder if life will exist on Mars in the future.

How does the author develop the point that Mars is like Earth?

Roadrunners are birds that are well adapted and important to their desert environments. They live in the southwest regions of North America. Their name comes from their habit of running along the road, usually toward cars. They do this because they are extremely territorial and want to chase away intruders. Measuring 18–24 inches in height, these birds can run up to 26 miles per hour. Their bodies do not require any extra water to drink besides what they get from their food. A roadrunner's diet consists of a variety of insects, but they can prey on lizards and dangerous rattlesnakes.

How does the author support the point that roadrunners are well adapted to living in the desert?

The Pueblo Indian tribe settled in the areas that are now New Mexico and Arizona. Pueblos are well-known for the amazing homes and roads they built. Using adobe clay and stones, they created durable structures that have lasted for hundreds of years. Adobe material was made using the earth, water, and straw. These homes were built right into cliffs several stories high. The Pueblos also constructed many roads between their towns. The Great Road is a famous Pueblo road that ran for over 30 miles.

What main reason supports the point that Pueblos had amazing homes?

A drought happens when there is a lack of rainfall for a long time. Some areas of the world are more likely to experience a drought than others. People that live in those areas have to be cautious about how they use their daily water supply. When a drought happens, it directly affects their everyday lives. This extreme weather can also increase the chances of dangerous wildfires, landslides, and flash floods.

What evidence supports the point that a drought is extreme weather?

Peanuts are a type of seed called a legume because their seeds grow inside of a pod. However, they are very different from other legumes. First of all, peanuts are grown underground. All other legumes, such as beans, are grown above ground. Also, peanuts have a hard shell, whereas other legumes have soft pods. Lastly, peanuts can be used in a variety of ways. Most people enjoy peanuts ground into peanut butter, but they can also be boiled, roasted, eaten raw, or mixed into your favorite candy bar.

How does the author develop the point that peanuts are different than other legumes?

Madagascar is an island off the coast of Africa. It has such a rare population of animals and plants that some ecologists call it the eighth continent of the world. Over 70 percent of Madagascar's wildlife and 90 percent of its plants are found nowhere else in the world. The most common example is the lemur. All species of wild lemur can only be found on this African island. Due to deforestation, they are all currently classified as endangered. Madagascar is also home to the third-largest coral reef system called Toliara.

How does the author support the point that Madagascar is important to the lemur population?

Do you have a hard time tasting your food when you have a stuffy nose? The reason is behind your senses of smell and taste. They love to work together! Inside your nose are millions of hairs called cilia. These hairs work to send signals to your brain. Similarly, your tongue uses taste buds to send signals to your brain. You can only taste four different flavors, but you can smell around 10,000 different smells. The flavor of your food comes from a combination of what your tongue tastes and what your nose smells. If one of your senses is not working, you may find it hard to enjoy your meal.

What two reasons support the point that our senses work together?

The Red Sea is known for its beauty. Located between Asia and Africa, this small part of the Indian Ocean is the most northern tropical sea in the world. Reddish-colored algae bloom and float near the surface, giving the sea its name. It is also home to more than 1,200 different species of fish and 200 types of corals. There are many islands in the center of the Red Sea. They are all created by underwater volcanoes. This sea is one of the most traveled waterways on Earth.

What reason(s) does the author give to support that the Red Sea is beautiful?

Have you ever “hit a plateau”? This saying means that you are not getting anywhere with what you are trying to accomplish. The idea comes from a flat-topped landform that is found on all seven continents. Plateaus are elevated from the land around them, but their top is like a plate. They are usually found in mountainous regions. Plateaus can be formed by water, earthquakes, or volcanoes. The Tibetan Plateau is the largest and highest in the world.

What evidence supports the meaning of the saying “hit a plateau”?