Problem: On the Origin of Species:

He notes that both A. P. de Candolle and Charles Lyell had stated that all organisms are exposed to severe competition. Darwin emphasizes that he used the phrase "struggle for existence" in "a large and metaphorical sense, including dependence of one being on another"; he gives examples ranging from plants struggling against drought to plants competing for birds to eat their fruit and disseminate their seeds. He describes the struggle resulting from population growth: "It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms." He discusses checks to such increase including complex ecological interdependencies, and notes that competition is most severe between closely related forms "which fill nearly the same place in the economy of nature".

Why is competition so fierce between related species?
---
A: fill nearly the same place in the economy of nature".


Problem: In 1996 Brewster Kahle, with Bruce Gilliat, developed software to crawl and download all publicly accessible World Wide Web pages, the Gopher hierarchy, the Netnews (Usenet) bulletin board system, and downloadable software. The information collected by these "crawlers" does not include all the information available on the Internet, since much of the data is restricted by the publisher or stored in databases that are not accessible. These "crawlers" also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached. To overcome inconsistencies in partially cached web sites, Archive-It.org was developed in 2005 by the Internet Archive as a means of allowing institutions and content creators to voluntarily harvest and preserve collections of digital content, and create digital archives.
When did Brewster Kate and Bruce Gilliat develop software to download crawlwers?
---
Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The top 12 finalists originally included Mario Vazquez, but he dropped out citing 'personal reasons' and was replaced by Nikko Smith. Later, an employee of Freemantle Media, which produces the show, sued the company for wrongful termination, claiming that he was dismissed after complaining about lewd behavior by Vazquez toward him during the show.
What company produces the show?
A: Freemantle Media


Context and question: Some modern day physicists and science writers—such as Paul Davies and John Gribbin—have argued that materialism has been disproven by certain scientific findings in physics, such as quantum mechanics and chaos theory. In 1991, Gribbin and Davies released their book The Matter Myth, the first chapter of which, "The Death of Materialism", contained the following passage:
Who believes materialism has been proven by scientific findings? 
Answer: unanswerable


Question: The interceptor aircraft (or simply interceptor) is a type of fighter aircraft designed specifically to intercept and destroy enemy aircraft, particularly bombers, usually relying on high speed and altitude capabilities. A number of jet interceptors such as the F-102 Delta Dagger, the F-106 Delta Dart, and the MiG-25 were built in the period starting after the end of World War II and ending in the late 1960s, when they became less important due to the shifting of the strategic bombing role to ICBMs. Invariably the type is differentiated from other fighter aircraft designs by higher speeds and shorter operating ranges, as well as much reduced ordnance payloads.
Is there an answer to this question: When were interceptors like the F-102 Delta Dagger first built?

Answer: after the end of World War II


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In 2006 and 2007, the world used approximately 2.4 megatonnes (5.3×109 lb) of pesticides, with herbicides constituting the biggest part of the world pesticide use at 40%, followed by insecticides (17%) and fungicides (10%). In 2006 and 2007 the U.S. used approximately 0.5 megatonnes (1.1×109 lb) of pesticides, accounting for 22% of the world total, including 857 million pounds (389 kt) of conventional pesticides, which are used in the agricultural sector (80% of conventional pesticide use) as well as the industrial, commercial, governmental and home & garden sectors.Pesticides are also found in majority of U.S. households with 78 million out of the 105.5 million households indicating that they use some form of pesticide. As of 2007, there were more than 1,055 active ingredients registered as pesticides, which yield over 20,000 pesticide products that are marketed in the United States.
How maney pesticides are offered for sale in the US?
A:
over 20,000