For any animal, survival requires maintaining a variety of parameters of bodily state within a limited range of variation: these include temperature, water content, salt concentration in the bloodstream, blood glucose levels, blood oxygen level, and others. The ability of an animal to regulate the internal environment of its body—the milieu intérieur, as pioneering physiologist Claude Bernard called it—is known as homeostasis (Greek for "standing still"). Maintaining homeostasis is a crucial function of the brain. The basic principle that underlies homeostasis is negative feedback: any time a parameter diverges from its set-point, sensors generate an error signal that evokes a response that causes the parameter to shift back toward its optimum value. (This principle is widely used in engineering, for example in the control of temperature using a thermostat.)
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Homeostasis is like what household tool?
Ah, so.. a thermostat.

Many rescue teams, including that of the Taipei Fire Department from Taiwan, were reported ready to join the rescue effort in Sichuan as early as Wednesday. However, the Red Cross Society of China said that (on May 13) "it was inconvenient currently due to the traffic problem to the hardest hit areas closest to the epicenter." The Red Cross Society of China also stated that the disaster areas need tents, medical supplies, drinking water and food; however it recommended donating cash instead of other items, as it had not been possible to reach roads that were completely damaged or places that were blocked off by landslides. Landslides continuously threatened the progress of a search and rescue group of 80 men, each carrying about 40 kg of relief supplies, from a motorized infantry brigade under commander Yang Wenyao, as they tried to reach the ethnically Tibetan village of Sier at a height of 4000 m above sea level in Pingwu county. The extreme terrain conditions precluded the use of helicopter evacuation, and over 300 of the Tibetan villagers were stranded in their demolished village for five days without food and water before the rescue group finally arrived to help the injured and stranded villagers down the mountain.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Where were the soldiers under commander Yang Wenyao trying to go?
Ah, so.. Tibetan village of Sier

All YouTube users can upload videos up to 15 minutes each in duration. Users who have a good track record of complying with the site's Community Guidelines may be offered the ability to upload videos up to 12 hours in length, which requires verifying the account, normally through a mobile phone. When YouTube was launched in 2005, it was possible to upload long videos, but a ten-minute limit was introduced in March 2006 after YouTube found that the majority of videos exceeding this length were unauthorized uploads of television shows and films. The 10-minute limit was increased to 15 minutes in July 2010. If an up-to-date browser version is used, videos greater than 20 GB can be uploaded.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What time limit was introduced in March 2005?
Ah, so..
unanswerable