17. The method of claim 13 , comprising: comparing the occurrence ratios of the clean text with the occurrence ratios of the foreign text; and removing words from the clean text which have an OR less than the OR of the foreign text, to generate foreign-word-free clean text.
17. The method of claim 13 , comprising: comparing the occurrence ratios of the clean text with the occurrence ratios of the foreign text; and removing words from the clean text which have an OR less than the OR of the foreign text, to generate foreign-word-free clean text. 18. The method of claim 17 , wherein said removing words is effected in accordance with the following: 
 If OR in the clean text<Y % and the OR in the foreign text>Z %, then remove the word from the clean text, where Y % is within a range of: at least about 0.0007%; and up to about 100%; and Z % is within a range of at least about 0%; and up to about 5%.