另一种选择是使用 :after 伪标签。
Here is your Account number: <span class="AccountNumber"><span>12345</span><span>12</span><span>1234</span></span>
.AccountNumber span:before
{
content: " ";
}
http://jsfiddle.net/chrisvenus/DUsUN/
Though that might depend on your browser compatibility requirements...
Edit: Thanks to jasssonpet for pointing out to me that the implementation of copying differs by browsers... FF and chrome do not copy the spaces added this way. IE does. This means this is probably not the best solution but still an interesting one to note so I'm not getting rid of it. :)