TASK DEFINITION: Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
PROBLEM: 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.

SOLUTION: complete the following sentence. as molecules are moving against their concentration gradients, active transport cannot occur without __________.

PROBLEM: Mirza Tahir Hussain (born 1 June 1970) is a British man paroled on 17 November 2006 after spending 18 years on death row in Pakistan for the murder of a taxicab driver named Jamshed Khan in 1988, a crime which he says he committed in self-defence, as Khan pulled out a gun and tried to sexually assault him.

SOLUTION: Which crime Mirza Tahir Hussain is considered to have commited?

PROBLEM: ''Nothing Good Happens After 2 A.M.'' is the 18th episode in the first season of the television series How I Met Your Mother.

SOLUTION:
What series is the episode Nothing Good Happens After 2 A.M. part of?