Article: The earliest known avialan fossils come from the Tiaojishan Formation of China, which has been dated to the late Jurassic period (Oxfordian stage), about 160 million years ago. The avialan species from this time period include Anchiornis huxleyi, Xiaotingia zhengi, and Aurornis xui. The well-known early avialan, Archaeopteryx, dates from slightly later Jurassic rocks (about 155 million years old) from Germany. Many of these early avialans shared unusual anatomical features that may be ancestral to modern birds, but were later lost during bird evolution. These features include enlarged claws on the second toe which may have been held clear of the ground in life, and long feathers or "hind wings" covering the hind limbs and feet, which may have been used in aerial maneuvering.

Question: Avian species such as Anchiornis huxleyi and Xiaotingia zhengi are from which time period?
Ans: late Jurassic period

Article: Ming government officials fought against each other, against fiscal collapse, and against a series of peasant rebellions. They were unable to capitalise on the Manchu succession dispute and installation of a minor as emperor. In April 1644, the capital at Beijing was sacked by a coalition of rebel forces led by Li Zicheng, a former minor Ming official, who established a short-lived Shun dynasty. The last Ming ruler, the Chongzhen Emperor, committed suicide when the city fell, marking the official end of the dynasty.

Question: Who was Li Zicheng?
Ans: former minor Ming official

Article: Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:

Question: Where are some LEDs in machine vision systems found?
Ans: Optical computer mice

Article: Many annual events celebrate the diverse cultures of Houston. The largest and longest running is the annual Houston Livestock Show and Rodeo, held over 20 days from early to late March, is the largest annual livestock show and rodeo in the world. Another large celebration is the annual night-time Houston Pride Parade, held at the end of June. Other annual events include the Houston Greek Festival, Art Car Parade, the Houston Auto Show, the Houston International Festival, and the Bayou City Art Festival, which is considered to be one of the top five art festivals in the United States.

Question: What is the largest annual event held in Houston?
Ans:
Houston Livestock Show and Rodeo