Context and question: The first commutator DC electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832. Following Sturgeon's work, a commutator-type direct-current electric motor made with the intention of commercial use was built by the American inventor Thomas Davenport, which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools and a printing press. Due to the high cost of primary battery power, the motors were commercially unsuccessful and Davenport went bankrupt. Several inventors followed Sturgeon in the development of DC motors but all encountered the same battery power cost issues. No electricity distribution had been developed at the time. Like Sturgeon's motor, there was no practical commercial market for these motors.
What necessary technical development had yet to occur to make electric motors useful?
Answer: electricity distribution
Context and question: In mid-1944 Japan mobilized over 500,000 men and launched a massive operation across China under the code name Operation Ichi-Go, their largest offensive of World War II, with the goal of connecting Japanese-controlled territory in China and French Indochina and capturing airbases in southeastern China where American bombers were based. During this time, many of the newest American-trained Chinese units and supplies were forcibly locked in the Burmese theater under Joseph Stilwell set by terms of the Lend-Lease Agreement. Though Japan suffered about 100,000 casualties, these attacks, the biggest in several years, gained much ground for Japan before Chinese forces stopped the incursions in Guangxi. Despite major tactical victories, the operation overall failed to provide Japan with any significant strategic gains. A great majority of the Chinese forces were able to retreat out of the area, and later come back to attack Japanese positions such as Battle of West Hunan. Japan was not any closer in defeating China after this operation, and the constant defeats the Japanese suffered in the Pacific meant that Japan never got the time and resources needed to achieve final victory over China. Operation Ichi-go created a great sense of social confusion in the areas of China that it affected. Chinese Communist guerrillas were able to exploit this confusion to gain influence and control of greater areas of the countryside in the aftermath of Ichi-go.
Where did the Chinese stop the Operation Ichi-Go incursion?
Answer: Guangxi
Context and question: At the airport, where records have been kept since 1930, the record maximum temperature was 117 F (47 C) on June 26, 1990, and the record minimum temperature was 16 F (9 C) on January 4, 1949. There is an average of 145.0 days annually with highs of 90 F (32 C) or higher and an average of 16.9 days with lows reaching or below the freezing mark. Measurable precipitation falls on an average of 53 days. The wettest year was 1983 with 21.86 in (555 mm) of precipitation, and the driest year was 1953 with 5.34 in (136 mm). The most rainfall in one month was 7.93 in (201 mm) in August 1955. The most rainfall in 24 hours was 3.93 in (100 mm) on July 29, 1958. Snow at the airport averages only 1.1 in (2.8 cm) annually. The most snow received in one year was 8.3 in (21 cm) and the most snow in one month was 6.8 in (17 cm) in December 1971.
In what month did Tucson get the most rain?
Answer:
August 1955