Problem: In soil, microorganisms that reside in the rhizosphere (a zone that includes the root surface and the soil that adheres to the root after gentle shaking) carry out nitrogen fixation, converting nitrogen gas to nitrogenous compounds. This serves to provide an easily absorbable form of nitrogen for many plants, which cannot fix nitrogen themselves. Many other bacteria are found as symbionts in humans and other organisms. For example, the presence of over 1,000 bacterial species in the normal human gut flora of the intestines can contribute to gut immunity, synthesise vitamins, such as folic acid, vitamin K and biotin, convert sugars to lactic acid (see Lactobacillus), as well as fermenting complex undigestible carbohydrates. The presence of this gut flora also inhibits the growth of potentially pathogenic bacteria (usually through competitive exclusion) and these beneficial bacteria are consequently sold as probiotic dietary supplements.
Where do bacteria stay in soil?
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Answer: rhizosphere


Problem: As for Mac OS, System 7 was a 32-bit rewrite from Pascal to C++ that introduced virtual memory and improved the handling of color graphics, as well as memory addressing, networking, and co-operative multitasking. Also during this time, the Macintosh began to shed the "Snow White" design language, along with the expensive consulting fees they were paying to Frogdesign. Apple instead brought the design work in-house by establishing the Apple Industrial Design Group, becoming responsible for crafting a new look for all Apple products.
Which Mac is known for improving the handling of non-color graphics?
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Answer: unanswerable


Problem: The United States Air Force (USAF) is the aerial warfare service branch of the United States Armed Forces and one of the seven American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U.S. military to be formed, and is the largest and one of the world's most technologically advanced air forces. The USAF articulates its core functions as Nuclear Deterrence Operations, Special Operations, Air Superiority, Global Integrated ISR, Space Superiority, Command and Control, Cyberspace Superiority, Personnel Recovery, Global Precision Attack, Building Partnerships, Rapid Global Mobility and Agile Combat Support.
How many uniformed services are there in the United States?
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Answer:
seven