1. Yet no one had come up with a system which was infallible, or even close to it. 可就是没有一个人发明一种万无一失或接近万无一失的系统。
2. Irises are very good for recognition but you can put in dilation drops which change the iris completely. No technique is infallible, he said. 瞳仁认证虽然不错，但滴入扩瞳药水就可以轻易地改变瞳仁大小。所以说没有什么技术是绝对可靠的。
3. Learning incessantly is the surest way to keep pace with the times in the information age, and an infallible warrant of success in times of uncertainty. 持续的学习是在信息时代中跟时代并驾齐驱的最稳当的方式，也是在变动的世代中胜利的可靠保证。
