单项选择题 给定学生关系Students(学号，姓名，性别，学历，身份证号)，学历取值为本科生或研究生(含在职研究生)；教师关系Teachers(教师号，姓名，性别，身份证号，工资)。查询既是研究生，又是女性，且工资大于等于3500元的教师的身份证号和姓名的SQL语句如下：
Because the Internet ______ computers all over the world, any business that engages in electronic commerce instantly becomes an international business. One of the key issues that any company faces when it conducts international commerce is trust.
It is important for all businesses to establish ______ relationships with their customers. Companies with established reputations in the physical world often create trust by ensuring that customers know who they are. These businesses can rely on their ______ brand names to create trust on the Web. New companies that want to establish online businesses face a more difficult ______ because a kind of anonymity(匿名) exists for companies trying to establish a Web presence.
Because Web site visitors will not become customers unless they trust the company behind the site, a plan for establishing ______ is essential. Customers' inherent lack of trust in "strangers" on the Web is logical and to be expected: sellers on the Web cannot assume that visitors will know that the site is operated by a trustworthy business. 
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