This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
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Question: Around 2.5 million years ago (ending 11,600 years ago) was the geological period of the Ice Ages. Since approximately 600,000 years ago, six major Ice Ages have occurred, in which sea level dropped 120 m (390 ft) and much of the continental margins became exposed. In the Early Pleistocene, the Rhine followed a course to the northwest, through the present North Sea. During the so-called Anglian glaciation (~450,000 yr BP, marine oxygen isotope stage 12), the northern part of the present North Sea was blocked by the ice and a large lake developed, that overflowed through the English Channel. This caused the Rhine's course to be diverted through the English Channel. Since then, during glacial times, the river mouth was located offshore of Brest, France and rivers, like the Thames and the Seine, became tributaries to the Rhine. During interglacials, when sea level rose to approximately the present level, the Rhine built deltas, in what is now the Netherlands.

Answer: What period was 2.5 million years ago?

Question: On November 2, 2014, the Cubs announced that Joe Maddon had signed a five-year contract to be the 54th manager in team history. On December 10, 2014, Maddon announced that the team had signed free agent Jon Lester to a 6-year, $155 million contract. Many other trades and acquisitions occurred during the off season. The opening day lineup for the Cubs contained five new players including rookie right fielder Jorge Soler. Rookies Kris Bryant and Addison Russell were in the starting lineup by mid-April, and rookie Kyle Schwarber was added in mid-June. The Cubs finished the 2015 season with a record of 9765, third best in the majors. On October 7, in the 2015 National League Wild Card Game, Jake Arrieta pitched a complete game shutout and the Cubs defeated the Pittsburgh Pirates 40.

Answer: When did the Cubs announce that Joe Maddon had signed a five-year contract to be the 54th manager?

Question: As of August 2015, Jehovah's Witnesses report an average of 8.2 million publishersthe term they use for members actively involved in preachingin 118,016 congregations. In 2015, these reports indicated over 1.93 billion hours spent in preaching and "Bible study" activity. Since the mid-1990s, the number of peak publishers has increased from 4.5 million to 8.2 million. In the same year, they conducted "Bible studies" with over 9.7 million individuals, including those conducted by Witness parents with their children. Jehovah's Witnesses estimate their current worldwide growth rate to be 1.5% per year.

Answer:
What term do Jehovah's Witnesses use for members actively involved in preaching?