- Before money was invented, people traded animals and crops for the things they wanted.
- In ancient China, people traded shells, metal tools, and later paper made from deer skin for goods and services.
- The first coins were made of gold and silver around 700 BC in Lydia, located in modern-day Turkey. After Lydia, coin usage spread to Rome, Iran, and Greece.
- Before money was invented, people traded animals and crops for the things they wanted.
- In ancient China, people traded shells, metal tools, and later paper made from deer skin for goods and services.
- The first coins were made of gold and silver around 700 BC in Lydia, located in modern-day Turkey. After Lydia, coin usage spread to Rome, Iran, and Greece.
1. Corn is the most popular crop in the United States, with Iowa growing the most. More than half of US corn is grown in Iowa, Illinois, Nebraska, and Minnesota.
2. Corn is used for food like cornmeal, cornflakes, and popcorn. It is also used as animal feed and to make ethanol fuel.
3. Ethanol made from corn is sometimes added to gasoline to make it cheaper.
There are many different types of houses around the world. Houses can be large or small, and made from materials like wood, stone, mud, ice or cloth. Forest houses are often made from logs because trees are plentiful. Houses generally contain rooms for sleeping (bedrooms), cooking (kitchens), and bathing, as well as living rooms. Some also have basements under or attics above the main house structure. Most houses have doors for entering and exiting and windows to look outside and let in air. Houses vary in decoration from plain to fancy between different parts of the world.
American black bears and brown bears live in North America. Black bear cubs are born in the winter and stay with their mother in the den until summer, when they like to play outside. Brown bear cubs also stay with their mothers for 2-4 years. Both black bear and brown bear cubs eat berries, nuts, and other foods provided by their mothers. Brown bears can grow up to 10 feet tall and live in northern areas of the United States, Canada, and Eurasia.
Bees are insects that can fly using their wings. They come in yellow, red, and orange colors and have three main body parts - a head, body, and stinger which is used for defense. Bees have six legs and live on every continent except Antarctica, as it is too cold. They fly to collect pollen from flowers and mostly leave humans alone if not bothered.
There are many different kinds of fish that vary in size, color, diet, speed, weight, and length. The passage discusses that people currently know about 25,000 kinds of fish, but there are likely another 15,000 kinds that have yet to be discovered. It provides details about the largest, fastest, heaviest, and longest fish, such as the heaviest weighing 15 tons and the longest being certain shark species that can grow to 50 feet.
Frogs live both on land and in water. They have long back legs, short bodies, eyes that stick out, and no tails. Young frogs must have wet skin so they can breathe through it, while older frogs grow lungs to breathe with on land. Frogs lay their eggs in bodies of water like ponds and lakes. Some frogs have webbing between their toes to help them swim fast or toe pads to help them climb trees and rocks.
1) Dogs have helped humans for thousands of years by pulling sleds and assisting with tasks like farming, hunting, and fishing.
2) There is variety in dog sizes, from very small dogs only 6-8 inches tall to very big dogs about 3 feet tall.
3) Dogs have strong senses of smell, hearing, and for some, vision. They can smell 40 times better than humans and hear sounds humans cannot.
Plants need sunlight to photosynthesize and produce food. An experiment is described where a bucket is placed over grass to block sunlight. After a few days, the grass under the bucket is less green and after a week is very dull, as it cannot photosynthesize without sunlight. Removing the bucket allows the grass to regain its green color as it receives sunlight again.