To its fans, it is addictive. To the media, it is a promising money-maker. Sudoku, an old puzzle long popular in Japan is fast gaining (1)____(popular) the world over. In Britain, a sudoku book is a bestseller and national newspapers are competing (2)____(feverish) to publish the most, and the most fiendish, puzzles. Meanwhile, the puzzle is being published in newspapers from Australia to Croatia to America. Even the New York Times is considering (3) intr____ sudoku in its Sunday magazine, alongside its venerated crossword.　　The game’s appeal is that its rules are as simple as its solution is complex. On a board of nine-by-nine (4) sq____, most of them empty, players must fill in each one (5)____ a number so that each row (left to right), column (top to bottom) and block (in bold lines) contains 1 to 9. Advanced (6) ver____ use bigger boards or add letters from the alphabet.　　Sudoku—the Japanese word combines “number” and “single”—seems perfectly suited to modern times, a puzzle for an era when people are more (7) nu____ than literate. And like globalism itself, sudoku transcends borders by (8)____(require) no translation.　　The overall business of puzzles is hard to measure (9)____ revenues in America from magazines, syndicated newspaper sales, books, and online and phone services are almost $200m annually. The New York Times earns millions of dollars a year from its crosswords and hundreds of thousands from a special phone service that provides (10)____(hint). Over 30,000 people pay $35 a year for the newspaper’s e-mail version.