But as soon as the threat is passed, the entrance is open again, and maybe there are situations in computer security where operating costs are low enough that we could just block access temporarily in response to an immediate threat, and then open it again, instead of trying to build a permanent firewall or fortress.
但是一旦危险解除, 入口就会重新开启, 或许我们也可以联想到 在计算机安全领域 这个领域的运营成本也低到 我们可以临时的中断网络访问 以应对临时的威胁, 稍后继续开放, 而不是现在的做法 尝试构造一个永久的防火墙.