TASK DEFINITION: Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
PROBLEM: Context: During active transport, molecules move from an area of low concentration to an area of high concentration. This is the opposite of diffusion, and these molecules are said to flow against their concentration gradient. Active transport is called "active" because this type of transport requires energy to move molecules. ATP is the most common source of energy for active transport. As molecules are moving against their concentration gradients, active transport cannot occur without assistance. A carrier protein is always required in this process. Like facilitated diffusion, a protein in the membrane carries the molecules across the membrane, except this protein moves the molecules from a low concentration to a high concentration. These proteins are often called "pumps" because they use energy to pump the molecules across the membrane. There are many cells in your body that use pumps to move molecules. For example, your nerve cells (neurons) would not send messages to your brain unless you had protein pumps moving molecules by active transport. The sodium-potassium pump ( Figure 1.1) is an example of an active transport pump. The sodium-potassium pump uses ATP to move three sodium (Na+ ) ions and two potassium (K+ ) ions to where they are already highly concentrated. Sodium ions move out of the cell, and potassium ions move into the cell. How do these ions then return to their original positions? As the ions now can flow down their concentration gradients, facilitated diffusion returns the ions to their original positions either inside or outside the cell.
Question: which statement is true concerning active transport?

SOLUTION: during active transport, molecules move from an area of low concentration to

PROBLEM: Context: In the Caucasus region of Russia, nearly 50 out of every 100,000 people live to celebrate their 100th birthday, and many don't stop at 100! By comparison, in America only 3 people in 100,000 reach 100. But these Russian old people aren't alone. The Pakistanis, who live high in the Himalaya Mountains, and the Ecuadorans of the Andes Mountains seem to share the secret of long life, too. These people remain healthy in body and spirit despite the passage of time. While many older persons in industrial societies become weak and ill in their 60s and 70s, some Caucasians aged 100 to 140, work in the fields beside their great-great-grandchildren. Even the idea of aging is foreign to them. When asked "at what age does youth end?"most of these old people had no answer. Several replied, "Well, perhaps at age 80." What accounts for this ability to survive to such old age, and to survive so well?First of all, hard physical work is a way of life for all of these long-lived people. They begin their long days of physical labor as children and never seem to stop. For example, Mr . Rustam Mamedov is 142 years of age. His wife is 116 years old. They have been married for 90 years. Mr. Mamedov has no intention of retiring from his life as a farmer. "Why?What else would I do?"he asks. All these people get healthful rewards from the environment in which they work. They all come from mountainous regions. They live and work at elevations of 1,660 to 1,000 meters above sea level. The air has less oxygen and is pollution-free. This reduced-oxygen environment makes the heart and blood vessel system stronger. Another factor that may contribute to the good health of these people is their isolation. To a great extent, they are separated from the pressures and worries of industrial society. Inherited factors also play some role. Most of the longest-lived people had parents and grandparents who also reached very old ages. Good family genes may, therefore, be one factor in living longer.
Question: What is the main way of life for all of these long-lived people?

SOLUTION: hard physical work.

PROBLEM: Context: In 2009, 78.5% of Dallas (city) commuters drive to work alone. The 2009 modal share for Dallas (city) commuters are 10.7% for carpooling, 3.9% for transit, 1.9% for walking, and .1% for cycling. In 2015, the American Community Survey estimated modal shares for Dallas (city) commuters of 75.4% for driving alone, 12.8% for carpooling, 3.5% for riding transit, 1.9% for walking, and .2% for cycling. The city of Dallas has a higher than average percentage of households without a car. In 2015, 10.2 percent of Dallas households lacked a car, and decreased to 9.1 percent in 2016. The national average was 8.7 percent in 2016. Dallas averaged 1.59 cars per household in 2016, compared to a national average of 1.8.
Question: Which group in percent of commuters in Dallas in 2009 is larger: transit or cycling?

SOLUTION:
transit