1The men in the trenches at night are ever on the alert.
2The whole forest seemed to be on the alert-astirand in suspense.
3Morning arrived in good time, and the boys were on the alert.
4Dan was on the alert at once; he loved to torment Betty.
5Outside the room, a squad of armed guards was on the alert.
6All day the garrison and population of Irkutsk were on the alert.
7The people were on the alert, nor did the conspirators hold back.
8The promises of reward have set all evil-minded people on the alert.
9After the first instant of frozen horror she was on the alert.
10The old hunter told all of them to be on the alert.
11At night he knew the savages would be most on the alert.
12Therefore at the unusual sound Billy was on the alert at once.
13The troops sprang to arms, and remained on the alert until daybreak.
14Mr. Tyler thought the same, and he was actively on the alert.
15Being always on the alert for squalls, I ran to the bow.
16Fossicking about, one kept on the alert for the feel of woodwork.