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.

Context: Sir Wilfred Robarts, a famed barrister, has just been released from the hospital in which he stayed for two months following a heart attack. Returning to his practise of law, he takes the case of Leonard Vole, an unemployed man who is accused of murdering his elderly friend, Mrs. Emily French. Vole claims he's innocent, although all evidence points to him as the killer, but his alibi witness, his cold German wife Christine, instead of entering the court as a witness for the defense, becomes the witness for the prosecution and defiantly testifies that her husband is guilty of the murder. Sir Wilfred believes there's something suspicious going on with the case, particularly with Mrs. Vole. 
 Question: What is Sir Wilfred Robert's profession?
barrister

Context: The median age in the city was 35.1 years. 24.2% of residents were under the age of 18; 7.9% were between the ages of 18 and 24; 33.8% were from 25 to 44; 24.6% were from 45 to 64; and 9.5% were 65 years of age or older. The gender makeup of the city was 48.6% male and 51.4% females. 
 Question: Which age group is larger: under the age of 18 or 18 and 24?
under the age of 18

Context: The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given time since it started moving. Q: In the Figure 1.1, what distance has the object traveled from the starting point by the time 5 seconds have elapsed? A: The object has traveled a distance of 50 meters. In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. Its easy to calculate the average velocity of a moving object from a position-time graph. Average velocity equals the change in position (represented by d) divided by the corresponding change in time (represented by t): velocity = d t For example, in Graph 2 in the Figure 1.2, the average velocity between 0 seconds and 5 seconds is: d t 25 m 0 m = 5 s0 s 25 m = 5s = 5 m/s velocity = 
 Question: the slope of a position-time graph can be used to find the moving objects

velocity.