The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. Knowing it acts like a magnet is one thing. Knowing why it acts like a magnet is more difficult. In fact, finding out why is a fairly recent discovery. To find out why required new technology. It was the seismograph that made it possible to learn why the Earth acted like a magnet. Seismograph are used to study earthquakes. By studying earthquake waves they were able to learn about Earths interior. They discovered that Earth has an inner and outer core. The outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated here. It is caused by the motion of this liquid metal. The liquid metal moves as Earth spins on its axis.

Question: "When was it first suggested that Earth was a magnet?"

Response: "In 1600"
OPTIONS:
- no
- yes

A: yes

When land is cleared, habitats are lost. It may be cleared for agriculture. It may also be used for building new homes or businesses. Within the past 100 years, the amount of land used for agriculture has almost doubled. Land used for grazing cattle has more than doubled. Many wetlands have also been lost to agriculture. The U.S. has lost almost all the natural tall-grass prairies. Thee areas of tall thick grass have virtually disappeared. These areas of land had thick fertile soil. Their grasses had very deep root systems. These deep and thick roots reduced the amount of soil erosion. They also were home to many plants and animals. Prairies were wonderful places. They were home to colorful flowers, prairie dogs, and herds of bison.

Question: "Why may land be cleared?"

Response: "100 years"
OPTIONS:
- no
- yes

A: no

(CNN) -- The U.S. space shuttle program retired in 2011, leaving American astronauts to hitchhike into orbit. But after three long years, NASA's successor is almost ready to make an entrance. Orion, the agency's newest manned spaceship, is being prepared for its first mission in December. In future missions, it will journey into deep space -- to Mars and beyond -- farther than humans have ever gone before. Orion comes loaded with superlatives. It boasts the largest heat shield ever built and a computer 400 times faster than the ones on the space shuttles. It will be launched into space on the most powerful rocket NASA has ever made. No astronauts will be aboard the December flight, which will test the spacecraft's systems for future manned missions. Final work on the spacecraft is under way at the Kennedy Space Center in Florida. Orion came one step closer to completion this month with the stacking of the crew module atop the service module. "Now that we're getting so close to launch, the spacecraft completion work is visible every day," Orion Program Manager Mark Geyer said in a statement. A 3,600-mile journey When complete, the Orion capsule will resemble a fencing foil, with a tall spire shooting up from a rounded base. At the top will sit a launch abort system, with downward-facing thrusters that would save the crew from a jarring crash in the event of a rocket malfunction. The bottom portion, the service module, will perform various functions such as in-space propulsion and cargo storage. Nestled between the two will be the crew module, capable of supporting human life from launch until recovery. Attached to the service module will be a United Launch Alliance Delta IV Heavy rocket. For the first time since the space shuttle's debut launch in 1981, the crew compartment will ride on the tip of the rocket rather than hanging onto its side, evoking the configuration of the famous Apollo or Gemini missions.

Question: "The crew module is nestled between which two systems or modules?"

Response: "Fencing foil, with a tall spire"
OPTIONS:
- no
- yes

A:
no