确保万无一失

insure that no impediment shall arise

All the electronics in the world cannot insure that no impediment shall arise. 世上没有哪种电子器材能完全确保万无一失

to make extra certain

To make extra certain, a police helicopter kept watch from the skies. 

为确保万无一失，一架警用直升机一直在空中警戒

to be sure of success

We made careful preparations for climbing the mountain, so as to be sure of success. 

我们为这次登山活动做了精心准备, 以确保万无一失.