没有一个;
例句:
No-one could use the computer unless they had a password.
除非知道密码,否则谁也用不了那台计算机。
No one should mistake how serious the issue is.
任何人都不该低估该问题的严重性。
No one knows how many people currently surf the Net.
没人知道现在有多少人在网上冲浪。