A search engine is a information retrieval program that constantly collects information on the Web, following links in Web sites and reading Web pages. The search results are presented in a list format and are called as hits.

A metasearch engine is a search tool that uses another search engine's data to produce its own results from the Internet. These engines take input from a user and simultaneously send out queries to third party search engines for results. It searches other search engines rather than individual Web sites.

Examples of Metasearch engine includes - Dogpile, Zoo, Yabado, Metager, etc...

Cryogenic Engines find applications in Rocket technology. A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel or oxidizer, that is, its fuel or oxidizer are gases liquefied and stored at very low temperatures. Notably, these engines were one of the main factors of NASA's success in reaching the Moon by the Saturn V rocket.

A search engines are a software systems used for searching about any information in the world on the web.

Search engines like Google, Bing, Internet explorer, Yahoo, etc... functions by providing relevant search results for the keywords user searches. 

Hence, the given statement is TRUE.

The above-given statement is absolutely true. Poorly tuned engines of vehicles will not get good gas mileage.

A poorly running engine may lose power that is needed for normal driving and emergencies, may not start, gets poor fuel economy, pollutes the air, and could stall when you are on the road causing a traffic problem.

2 engines of former type for one hour consumes (2 x 24)/(6 x8) = 1 metric ton 

i.e. 3 engines of latter type consumes 1 ton for one hour

Hence 9 engines consumes 3 tons for one hour

For 15 hours it is 15 x 3 = 45 metric tonnes.

1 : InnoDB provides us row level locking while MyISAM provides us table level locking.

2 : InnoDB offers foreign key constraints wheres in MyISAM does not have foreign key constraints.

3 : InnoDB does not have full text search wheres MyISAM provides us full text search.