Problem: According to Sun Jiadong, the chief designer of the navigation system, "Many organizations have been using our system for a while, and they like it very much."
Who is the chief designer of the BeiDou navigation system?
The answer is the following: Sun Jiadong

Problem: The discovery of gold in Victoria in mid 1851 led to the Victorian gold rush, and Melbourne, which served as the major port and provided most services for the region, experienced rapid growth. Within months, the city's population had increased by nearly three-quarters, from 25,000 to 40,000 inhabitants. Thereafter, growth was exponential and by 1865, Melbourne had overtaken Sydney as Australia's most populous city. Additionally, Melbourne along with the Victorian regional cities of Ballarat and Geelong became the wealthiest cities in the world during the Gold Rush era.
How much did Melbourne's population increase within months of the gold rush?
The answer is the following: three-quarters, from 25,000 to 40,000 inhabitants

Problem: In mid-2004 Madonna embarked on the Re-Invention World Tour in the U.S., Canada, and Europe. It became the highest-grossing tour of 2004, earning around $120 million and became the subject of her documentary I'm Going to Tell You a Secret. In November 2004, she was inducted into the UK Music Hall of Fame as one of its five founding members, along with The Beatles, Elvis Presley, Bob Marley, and U2. In January 2005, Madonna performed a cover version of the John Lennon song "Imagine" at Tsunami Aid. She also performed at the Live 8 benefit concert in London in July 2005.
When was the Re-Invention World Tour kick off?
The answer is the following: mid-2004

Problem: The Diwan of Umar, assigning annuities to all Arabs and to the Muslim soldiers of other races, underwent a change in the hands of the Umayyads. The Umayyads meddled with the register and the recipients regarded pensions as the subsistence allowance even without being in active service. Hisham reformed it and paid only to those who participated in battle. On the pattern of the Byzantine system the Umayyads reformed their army organization in general and divided it into five corps: the centre, two wings, vanguards and rearguards, following the same formation while on march or on a battle field. Marwan II (74050) abandoned the old division and introduced Kurdus (cohort), a small compact body. The Umayyad troops were divided into three divisions: infantry, cavalry and artillery. Arab troops were dressed and armed in Greek fashion. The Umayyad cavalry used plain and round saddles. The artillery used arradah (ballista), manjaniq (the mangonel) and dabbabah or kabsh (the battering ram). The heavy engines, siege machines and baggage were carried on camels behind the army.
What style of dress did Arab troops wear under Marwan II?
The answer is the following:
Greek