E-mail is the most widely used service-you can exchange e-mail with millions of people all over the world. 电子邮件是应用最广的一项服务，你可以与世界上千百万人互换邮件人们可用电子邮件交换任何可用信件或电话来交换的内容。
With the first set strands removed from the frame, we can then add different set strands, which bind to the central region and cross over there. 一旦将第一个设定股从结构中移除，我们就可以加入不同的设定股，让它结合到中央区并在那儿产生互换。
