TASK DEFINITION: Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
PROBLEM: Passage: Much of the work of the Scottish Parliament is done in committee. The role of committees is stronger in the Scottish Parliament than in other parliamentary systems, partly as a means of strengthening the role of backbenchers in their scrutiny of the government and partly to compensate for the fact that there is no revising chamber. The principal role of committees in the Scottish Parliament is to take evidence from witnesses, conduct inquiries and scrutinise legislation. Committee meetings take place on Tuesday, Wednesday and Thursday morning when Parliament is sitting. Committees can also meet at other locations throughout Scotland. Question: Taking evidence from witnesses is one of committees' what?

SOLUTION: principal role

PROBLEM: Passage: In the laboratory, stratigraphers analyze samples of stratigraphic sections that can be returned from the field, such as those from drill cores. Stratigraphers also analyze data from geophysical surveys that show the locations of stratigraphic units in the subsurface. Geophysical data and well logs can be combined to produce a better view of the subsurface, and stratigraphers often use computer programs to do this in three dimensions. Stratigraphers can then use these data to reconstruct ancient processes occurring on the surface of the Earth, interpret past environments, and locate areas for water, coal, and hydrocarbon extraction. Question: What tool do stratigraphers use to see their data in three dimensions?

SOLUTION: computer programs

PROBLEM: Passage: Since the 2005 revival, the Doctor generally travels with a primary female companion, who occupies a larger narrative role. Steven Moffat described the companion as the main character of the show, as the story begins anew with each companion and she undergoes more change than the Doctor. The primary companions of the Ninth and Tenth Doctors were Rose Tyler (Billie Piper), Martha Jones (Freema Agyeman), and Donna Noble (Catherine Tate) with Mickey Smith (Noel Clarke) and Jack Harkness (John Barrowman) recurring as secondary companion figures. The Eleventh Doctor became the first to travel with a married couple, Amy Pond (Karen Gillan) and Rory Williams (Arthur Darvill), whilst out-of-sync meetings with River Song (Alex Kingston) and Clara Oswald (Jenna Coleman) provided ongoing story arcs. The tenth series will introduce Pearl Mackie as Bill, the Doctor's newest traveling companion. Question: Who were the secondary companions of the Ninth and Tenth Doctors?

SOLUTION:
Mickey Smith (Noel Clarke) and Jack Harkness (John Barrowman)