Static electricity is like a teeter-totter. What happens if a teeter-totter is balanced? Correct! It does not move. What about when its not balanced? Yes, it will now begin to move. Charges move when they are not balanced. Charges can build up by friction. Maybe you rub your feet on a wool mat or carpet. Rubber soled shoes readily gain charges. The wool carpet easily gives up charges. The two items become unbalanced. One item has a positive charge. The other has a negative charge. The difference in charge is called static electricity. Just like the teeter-totter, something is going to move. Positive charges build up on the mat. Negative charges build up on you.

Question: "When static electricity is balanced like a teeter-totter, what happens?"

OPTIONS:
- no
- yes

Answer: ""It does not move.""

Response: yes

Density is also an important physical property of matter. The concept of density combines what we know about an objects mass and volume. Density reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter is more dense. Differences in density of matter explain many phenomena. It explains why helium balloons rise. It explains why currents such as the Gulf Stream flow through the oceans. It explains why some things float in or sink. You can see this in action by pouring vegetable oil into water. You can see a colorful demonstration in this video.

Question: "What are three examples of density given in the article?"

OPTIONS:
- no
- yes

Answer: "How a hovercraft works"

Response: no

There once was a guy named Kevin and girl named Erin. They really liked spending time together. One day, Kevin traveled from his home in the United States of America to Erin's house in England. They then thought to take a sudden trip around the world. They first traveled by plane around Europe, where they saw many different people and sights. They then took a boat to Africa and Asia, where they went on a trip through the mountains. Later in the month, they traveled to China by train and were allowed to see how different life was over there. Next they took another plane to Australia, where they had a lot of fun seeing kangaroos and a different type of English speaking people. After spending a week in Australia, Kevin and Erin took a really long plane ride to North America, where they drove across the land. They saw everything from the mountains to forests. They even got to visit the beach! Because they had so much fun, Kevin returned home with Erin to England where they hung out and spent the next few days and months talking about all of the neat things they saw and did on their trip.

Question: "Who looked spending time with Kevin?"

OPTIONS:
- no
- yes

Answer: "The girl, Erin"

Response: yes

Hundreds of thousands of years before China was to become the world's longest-running civilization, the prologue was enacted by means of the flicker of a carefully tended fire. Peking Man, a forebear of Homo sapiens, achieved a mastery of fire. We might call it the first Chinese invention. Not that he devised flint and steel, matches, or any other way of creating fire. Peking Man simply learned how to capture flame, perhaps from a forest fire, and keep it alight. He thus enjoyed two revolutionary luxuries: light and heat. Technologically and sociologically, it was a phenomenal breakthrough: with fire, communities could live year 'round in one cave, in which cooking and even smelting could be pursued. And so, by 600,000 b.c., about 50 km (31 miles) southwest of present-day Beijing, the ancestors of mankind were ready to settle down. Several hundred thousand years later, when Marco Polo reached the capital of China, he was astonished by a further development in fire technology. The Chinese, he announced, used black stones dug out of mountains as fuel. Europeans did not yet have a word for "coal," nor had they discovered a use for it. The First Dynasty The confluence of mythology and history in China took place around 4,000 years ago during what is referred to as the Xia (Hsia) Dynasty. This was still the Stone Age, but the people are thought to have made silk from thread produced by the worms they cultivated on the leaves of their mulberry trees. And written language (which evolved as early as 4,500 to 5,000 years ago) was already in use, originally by oracles and then by official scribesChina's first scholars. During the second of the quasi-legendary dynasties, the Shang (from about the 16th to 11th centuries b.c.), the Chinese developed an interest in art. Careful geometric designs as well as dragon and bird motifs adorned bowls and implements. And with the arrival of the Bronze Age, the Chinese created bronze vessels of such beauty and originality that, until modern times, archaeologists refused to believe they were cast 3,000 years ago. The Shang Dynasty gave rise to the concept of one Chinese nation under one government.

Question: "Who designed geometric bowls and bronze vessels?"

OPTIONS:
- no
- yes

Answer: "Homosapiens"

Response:
no