This time they were sharp on the qui vive, and the bulls, being well to the front, were keeping a bright look-out.
"Eight Years' Wandering in Ceylon" by Samuel White Baker
As I remember the New England boy (and I am very intimate with one), he used to be on the qui vive in the spring for the sap to begin running.
"Being a Boy" by Charles Dudley Warner
Each moment of the day and night they had to be on the qui vive, for it swarmed with hostile enemies, both human, inhuman, and climatical.
"The Empire Makers" by Hume Nesbit