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.

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?
Mickey Smith (Noel Clarke) and Jack Harkness (John Barrowman)

Passage: The correlation between capitalism, aristocracy, and imperialism has long been debated among historians and political theorists. Much of the debate was pioneered by such theorists as J. A. Hobson (1858–1940), Joseph Schumpeter (1883–1950), Thorstein Veblen (1857–1929), and Norman Angell (1872–1967). While these non-Marxist writers were at their most prolific before World War I, they remained active in the interwar years. Their combined work informed the study of imperialism and it's impact on Europe, as well as contributed to reflections on the rise of the military-political complex in the United States from the 1950s. Hobson argued that domestic social reforms could cure the international disease of imperialism by removing its economic foundation. Hobson theorized that state intervention through taxation could boost broader consumption, create wealth, and encourage a peaceful, tolerant, multipolar world order. Question: some debate that there is a correlation between capitalism, imperialism, and what?
aristocracy

Passage: The executive summary of the WG I Summary for Policymakers report says they are certain that emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases, resulting on average in an additional warming of the Earth's surface. They calculate with confidence that CO2 has been responsible for over half the enhanced greenhouse effect. They predict that under a 'business as usual' (BAU) scenario, global mean temperature will increase by about 0.3 °C per decade during the [21st] century. They judge that global mean surface air temperature has increased by 0.3 to 0.6 °C over the last 100 years, broadly consistent with prediction of climate models, but also of the same magnitude as natural climate variability. The unequivocal detection of the enhanced greenhouse effect is not likely for a decade or more. Question: What does the WG I Summary for Policymakers report say human activities are doing to greenhouse gases?
substantially increasing the atmospheric concentrations