Passage: We are learning about life on Earth from a large satellite in space. Scientists built the satellite and used a rocket to launch it into space in 1998. It is the International Space Station, or ISS. Fifteen countries cooperated to build and operate it. The space station is about 250 miles above Earth and orbits, or circles, Earth sixteen times a day. It is a little longer than a United States football field and weighs almost one million pounds. Since 2000, people have lived and been active on the space station. One purpose of the ISS is to learn about living in space. Another is to conduct experiments.

The findings should make life better for people on Earth. Crews live on the ISS to gather information about space and Earth. A part that is like a big sunroom was attached to the space station in 2010. From here, astronauts can view Earth from space. They can observe lights of cities on Earth. They can watch other astronauts walking in space and study objects like asteroids in space. It is like having an eye on the universe.

In 2011, a new camera was placed on the space station that records happenings on Earth. The camera gives scientists a better tool to research natural events on Earth, such as lightning. It also gives information about the effects of human activities on our planet.

Space exploration began more than fifty years ago when Russia sent the first human-made satellite into orbit. In 1962, John Glenn, an American, orbited Earth. Then in 1969, people around the world watched Neil Armstrong’s walk on the surface of the moon.

The Skylab space station was launched in 1973. It had no human passengers. Later, a crew went to live on Skylab for a month. Three crews of astronauts lived on Skylab over the following nine months. Skylab proved it was possible for people to survive in space, but more importantly, they could work in orbit.

Scientists also figured out how to make a vehicle that could go back and forth between Earth and space. The next step was building such a space shuttle. Having such a vehicle would greatly simplify space exploration. Columbia, launched in 1981, was the first shuttle that carried astronauts. The space shuttles were larger than the earlier spaceships and they carried both pilots and scientists. Challenger, Discovery, Atlantis, and Endeavour later joined the fleet of shuttles.
The shuttle was important in building the International Space Station. At first, shuttle flights brought construction parts into space. Later, flights brought crews to live on the space station. Shuttles continue to serve as transportation for crews and supplies.
For more than ten years, the ISS’s space laboratory has given new information that will improve our future on Earth. Studies about infectious diseases have opened new ways to prevent those diseases. The benefits of ultrasound have increased due to its use on the space station. Ultrasound has deepened understanding about gravity’s effects on the human body. It also has helped to discover the health problems of people living on the space station.
We have learned new ways to treat heart disease, cancer, and bone disease as a result of research on the ISS. Experiments with plants have shown they can grow and be used as food on space expeditions. Moreover, they are a way to make air and water clean. We have already seen many good things come from experiments on the ISS. Scientists believe we will continue to benefit from work done in space.

Questions: Part A: How does the author organize “Watching Earth from Space”?

(1)by showing causes and effects in space

(2)by comparing and contrasting Earth and space

(3)by explaining sequence of events in exploring space

(4)by discussing problems and solutions in using a camera in space

Part B: Which sentence from the article best shows how the text is organized?

(1)"The space station is about 250 miles above Earth and orbits, or circles, Earth sixteen times a day.”

(2)"The camera gives scientists a better tool to research natural events on Earth, such as lightning.”

(3)"Columbia, launched in 1981, was the first shuttle that carried astronauts.”

(4)"Shuttles continue to serve as transportation for crews and supplies.”