With the rapid spread of the Internet every- where in the world, the 【C1】______ number of users, one of the most exciting developments on the Internet is E-commerce— 【C2】______ commerce. E-commerce has two forms, 【C3】______ business- to-business, or B-to-B, and business-to-consumer, or B-to-C. B-to-C was the first of these developments. It grew 【C4】______ from the first days when people started to buy things in their homes without going to a shop. First came “catalogue shopping” 【C5】______ you choose what you want from a catalogue 【C6】______ pictures and other details of everything that is 【C7】______ sale. You then send an order with a check by post and the things you have chosen 【C8】______ to your home. Then 【C9】______ “television shopping”, where 【C10】______ a catalogue, the items for sale are shown or 【C11】______ on television. 【C12】______ , the customer sends a check and the item is delivered to his or her home. Online shopping is the 【C13】______ development, where the “catalogue” is 【C14】______ on the Inter- net, combining the advantages of both the book catalogue and the television and indeed adding more 【C15】______ . The customer 【C16】______ his choice but rather than sending an order and a 【C17】______ through the post, he places the order and pays for it using his credit card, all using 【C18】______ . Many people worry about giving details of their credit card over the Internet and the danger that it may be deceitfully used. 【C19】______ , the general view is that with modem systems of secure encoding the dangers of the misuse of credit cards is 【C20】______ greater in a shop, garage or restaurant than using it for shopping on the Internet. 【C1】