infallible

她的判断几乎从不失误，大家都认为她是不会出错的。

Her judgment is nearly ___infallible, and everyone considers her incapable of mistakes.

这辆车的刹车系统绝对可靠，从未失效过。

The car's ___infallible braking system has never failed.

多年的精细测试创造了一套从未被突破的万无一失的安全规程。

Years of meticulous testing produced an ___infallible safety procedure that has never been breached.