Problem: The center of an atom is held together by powerful forces. This gives them a huge amount of stored energy. This type of energy is called nuclear energy. This energy can be released and used to do work. This happens in nuclear power plants where they split apart the nucleus of an atom. This splitting apart is called nuclear fission. Another type of nuclear energy happens in the Sun. Here the atoms nuclei are not split apart. Instead, the nuclei of the atoms are fused, or joined together. This process is called nuclear fusion. Some of the suns energy travels to Earth. This energy from nuclear fusion warms the planet and provides the energy for photosynthesis.

Question: "Some of the suns energy travels to earth, what is the energy used for on earth?"

Answer: "Conversion energy"

OPTIONS:
- no
- yes
Answer: no

Problem: So what is gravity? A typical definition of gravity is that it is a force. It causes an attraction between two masses. According to this definition, anything that has mass exerts a force. Any object exerts gravity on other objects. It does not matter how small it is, it has gravity. The more matter an object has, the more gravity it has. Your pencil has a tiny bit of gravity, but far too little to notice. What about a planet? It would have a lot of gravity. An objects gravity exerts a pull on other objects. Friction only occurs between objects that are touching. Gravity can act between objects that are not touching. In fact, gravity can act over very long distances. Where else can you feel gravity?

Question: "Does size matter as to whether or not an object has gravity?"

Answer: "yes"

OPTIONS:
- no
- yes
Answer: no

Problem: Little is known of the earliest Stone Age inhabitants of Europe's southwestern extremity. The ancient Greeks called them the Cynetes (or Cunetes). Whatever their origins, their culture evolved under the pressure and influence of foreign forces. Among the many invading armies that settled here and contributed to nascent Portuguese culture were Phoenicians, who settled in the area around 1,000 b.c., followed by the Celts, Iberians, Greeks, and Carthaginians. But it was the Romans, who arrived late in the third century b.c., who most greatly influenced all of Iberia. They built towns, industries, roads, and bridges, developed agriculture, and bequeathed the Latin language, of which Portuguese is a direct descendant. The Romans named the southwestern province of the peninsula Lusitania, oddly enough for one of the Celtiberian tribes they defeated, and by the third century a.d. had introduced Christianity. By the beginning of the fourth century the Algarve had a bishop in place, based in Faro. But Rome had already fallen into decay, and soon hordes of northern tribesmen took over the empire. The Algarve fell to the Visigoths in the mid-fifth century. Under Moorish Rule In a.d. 711, the Moors brought powerful armies from North Africa and launched a devastating attack on the Iberian peninsula, conquering much of what would become Spain and Portugal. They imposed Islam and left an indelible influence on the countryside and the population of the Algarve. The Moorish legacy can still be seen in the form of wells and waterwheels, squat white houses, the dark complexions of the people, and in the very name given the regiontaken from Al-Gharb, which means "country of the west" (when the Moors conquered the territory, it was the most westerly in the known world). The Moors governed their Iberian kingdoms from across the border in Seville, but the Algarve had its own regional capital and huge, invulnerable fortress. The capital was Chelb (or Xelb), and it was bigger and better defended than Lisbon. Today the town, known as Silves, is a provincial outpost whose only besiegers are busloads of tourists who climb the narrow streets up to the old Moorish ramparts.

Question: "Who imposed Islam on the population of the Algarve?"

Answer: "The Moors"

OPTIONS:
- no
- yes
Answer:
yes