'AMZN' is a four-letter word to many booksellers. The online retailer has been【C1】______of killing the bookselling industry. It certainly has【C2】______high street chains. But physical bookstore booksellers may【C3】______from Amazons latest announcement. On January 7th the company【C4】______the option of free delivery—which it calls 'Super Saver'—for book orders under ￡10 in Britain. This follows a【C5】______of the free-delivery option in July 2013, and【C6】______a similar scheme the retailer has introduced in America Amazons aim is to push customers towards its Prime service, which costs ￡49 a year for next-day delivery on orders of any price and also includes its locker service. This preferential treatment has proven【C7】______And they seem to buy more【C8】______than non-Prime customers. But the【C9】______carries a risk. Amazon may【C10】______casual book buyers, for whom a Prime subscription would be【C11】______from shopping online—and send them back to physical shops. Such buyers may【C12】______away from delivery charges that will now【C13】______25% or more of an orders total【C14】______when buying a single book from Amazon. Readers could simply【C15】______their online buying habits, for instance by keeping a reading list and buying several books at a time. And the higher delivery【C16】______will make many books on Amazon as【C17】______as in high-street shops. Yet Amazon, which had a【C18】______Christmas season, selling 426 items each second, may not care if buyers give up physical books.【C19】______surveys show that people prefer the【C20】______of a newly printed book and the ability to crack the spine of a page-turner. 【C1】