Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Q: Context: Mahjong, that favorite pastime of "old folks" in Shanghai, is finding a new audience among younger players, and many university students are becoming mad about this traditional Chinese game. Students at Fudan University have even formed a Mahjong club. This resurgence of the game, however, is not without its critics. Some people still associate the game with gambling and for many years Mahjong was banned in China. One critic, surnamed Meng, was quoted as saying, "Mahjong is a bad custom that will distract students from studies." But Yu Guangyuan, former vice-president of the Chinese Academy of Social Sciences , says Mahjong is a "healthy, scientific, friendly mind game." Mr. Yu's opinion seems to be shared by the majority of Chinese. They see the game as an activity that requires great concentration and intellectual skill. They also see the game as an important part of Chinese culture and a pastime that brings family and friends closer together. This Spring Festival many families will no doubt spend hours around the Mahjong table getting reacquainted with each other. For them, playing Mahjong is a way of spending quality family time. No one knows who invented Mahjong. Some say it was Confucius, others say the current form of the game was developed right here in Shanghai in the late19th century. It is certainly because of Shanghai that the game enjoys its worldwide popularity. It was brought to America in the 1920s and has since spread throughout Europe and other parts of Asia. There is now a World Championship of Mahjong which is held every year. This year's championship was held in Chongqing and attracted players from America, Europe and Russia, as well as students from Peking University, Tshinghua University and Nankai University. There was no prize money, but the players delighted in using their wits and their understanding of statistics and probability theory to defeat their clever opponents. Of course, Mahjong doesn't have to always be that intense. For young people it can be a way to relax and to socialize, a chance to get away from their computers and talk to other people face to face. So, this Spring Festival, why not get out the "old folks" tiles: it's good to be mad about Mahjong! 
 Question: What is the best title of the passage?

A: mad about mahjong
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Q: Context: General Sir Alfred Dudley Ward GCB, KBE, DSO (27 January 1905--28 December 1991), was a senior officer of the British Army who saw service during World War II and later became Governor of Gibraltar. 
 Question: What branch was Alfred Dudley Ward part of?

A: british army
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Q: Context: All archaeal and many bacterial genomes contain Clustered Regularly Interspaced Short Palindrome Repeats (CRISPR) and variable arrays of the CRISPR-associated (cas) genes that have been previously implicated in a novel form of DNA repair on the basis of comparative analysis of their protein product sequences. However, the proximity of CRISPR and cas genes strongly suggests that they have related functions which is hard to reconcile with the repair hypothesis. The protein sequences of the numerous cas gene products were classified into approximately 25 distinct protein families; several new functional and structural predictions are described. Comparative-genomic analysis of CRISPR and cas genes leads to the hypothesis that the CRISPR-Cas system (CASS) is a mechanism of defense against invading phages and plasmids that functions analogously to the eukaryotic RNA interference (RNAi) systems. Specific functional analogies are drawn between several components of CASS and proteins involved in eukaryotic RNAi, including the double-stranded RNA-specific helicase-nuclease (dicer), the endonuclease cleaving target mRNAs (slicer), and the RNA-dependent RNA polymerase. However, none of the CASS components is orthologous to its apparent eukaryotic functional counterpart. It is proposed that unique inserts of CRISPR, some of which are homologous to fragments of bacteriophage and plasmid genes, function as prokaryotic siRNAs (psiRNA), by base-pairing with the target mRNAs and promoting their degradation or translation shutdown. Specific hypothetical schemes are developed for the functioning of the predicted prokaryotic siRNA system and for the formation of new CRISPR units with unique inserts encoding psiRNA conferring immunity to the respective newly encountered phages or plasmids. The unique inserts in CRISPR show virtually no similarity even between closely related bacterial strains which suggests their rapid turnover, on evolutionary scale. Corollaries of this finding are that, even among closely related prokaryotes, the most commonly encountered phages and plasmids are different and/or that the dominant phages and plasmids turn over rapidly. We proposed previously that Cas proteins comprise a novel DNA repair system. The association of the cas genes with CRISPR and, especially, the presence, in CRISPR units, of unique inserts homologous to phage and plasmid genes make us abandon this hypothesis. It appears most likely that CASS is a prokaryotic system of defense against phages and plasmids that functions via the RNAi mechanism. The functioning of this system seems to involve integration of fragments of foreign genes into archaeal and bacterial chromosomes yielding heritable immunity to the respective agents. However, it appears that this inheritance is extremely unstable on the evolutionary scale such that the repertoires of unique psiRNAs are completely replaced even in closely related prokaryotes, presumably, in response to rapidly changing repertoires of dominant phages and plasmids. 
 Question: Gene silencing can be achieved by RNA interference (RNAi) in eukaryotic organisms. What is the name of the analogous process in prokaryotic organisms?

A:
crispr-cas
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