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.

[EX Q]: Occupancy sensors to allow operation for whenever someone is within the area being scanned can control lighting. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned. Doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Ultrasonic sensors transmit sound above the range of human hearing and monitor the time it takes for the sound waves to return. A break in the pattern caused by any motion in the area triggers the control. Ultrasonic sensors can see around obstructions and are best for areas with cabinets and shelving, restrooms, and open areas requiring 360-degree coverage. Some occupancy sensors utilize both passive infrared and ultrasonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures.
[EX A]: What sensor controls light with motion sensors? 

[EX Q]: Many parts of the Americas are still populated by indigenous peoples; some countries have sizable populations, especially Belize, Bolivia, Chile, Ecuador, Greenland, Guatemala, Mexico, and Peru. At least a thousand different indigenous languages are spoken in the Americas. Some, such as the Quechuan languages, Aymara, Guaraní, Mayan languages, and Nahuatl, count their speakers in millions. Many also maintain aspects of indigenous cultural practices to varying degrees, including religion, social organization, and subsistence practices. Like most cultures, over time, cultures specific to many indigenous peoples have evolved to incorporate traditional aspects, but also cater to modern needs. Some indigenous peoples still live in relative isolation from Western culture and a few are still counted as uncontacted peoples.
[EX A]: Belize, Chile and Greenland are just some countries with sizable populations of what peoples?

[EX Q]: Because of the low elevation, the islands that make up this nation are vulnerable to the effects of tropical cyclones and by the threat of current and future sea level rise. The highest elevation is 4.6 metres (15 ft) above sea level on Niulakita, which gives Tuvalu the second-lowest maximum elevation of any country (after the Maldives). The highest elevations are typically in narrow storm dunes on the ocean side of the islands which are prone to overtopping in tropical cyclones, as occurred with Cyclone Bebe, which was a very early-season storm that passed through the Tuvaluan atolls in October 1972. Cyclone Bebe submerged Funafuti, eliminating 90% of structures on the island. Sources of drinking water were contaminated as a result of the system's storm surge and the flooding of the sources of fresh water.
[EX A]:
What geological situation makes Tuvalu prone to storm damage?