instruction:
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.
question:
The study of plants is vital because they underpin almost all animal life on Earth by generating a large proportion of the oxygen and food that provide humans and other organisms with aerobic respiration with the chemical energy they need to exist. Plants, algae and cyanobacteria are the major groups of organisms that carry out photosynthesis, a process that uses the energy of sunlight to convert water and carbon dioxide into sugars that can be used both as a source of chemical energy and of organic molecules that are used in the structural components of cells. As a by-product of photosynthesis, plants release oxygen into the atmosphere, a gas that is required by nearly all living things to carry out cellular respiration. In addition, they are influential in the global carbon and water cycles and plant roots bind and stabilise soils, preventing soil erosion. Plants are crucial to the future of human society as they provide food, oxygen, medicine, and products for people, as well as creating and preserving soil.
answer:
Why are plants important to human life?


question:
The City of Tucson, Pima County, the State of Arizona, and the private sector have all made commitments to create a growing, healthy economy[citation needed] with advanced technology industry sectors as its foundation. Raytheon Missile Systems (formerly Hughes Aircraft Co.), Texas Instruments, IBM, Intuit Inc., Universal Avionics, Honeywell Aerospace, Sunquest Information Systems, Sanofi-Aventis, Ventana Medical Systems, Inc., and Bombardier Aerospace all have a significant presence in Tucson. Roughly 150 Tucson companies are involved in the design and manufacture of optics and optoelectronics systems, earning Tucson the nickname "Optics Valley".
answer:
What was Raytheon previously called?


question:
In 1913 the Zliten mosaic, a Roman mosaic famous for its many scenes from gladiatorial contests, hunting and everyday life, was discovered in the Libyan town of Zliten. In 2000 archaeologists working in Leptis Magna, Libya, uncovered a 30 ft length of five colorful mosaics created during the 1st or 2nd century AD. The mosaics show a warrior in combat with a deer, four young men wrestling a wild bull to the ground, and a gladiator resting in a state of fatigue, staring at his slain opponent. The mosaics decorated the walls of a cold plunge pool in a bath house within a Roman villa. The gladiator mosaic is noted by scholars as one of the finest examples of mosaic art ever seen — a "masterpiece comparable in quality with the Alexander Mosaic in Pompeii."
answer:

What scenes are depicted on the Zliten mosaic?