| 1. | Hearing this , i was instantly on the alert .
我一听这话，当下就警惕起来。 |
| 2. | They must be constantly on the alert for the enemy .
他们必须随时注意敌人。 |
| 3. | Old jolyon was on the alert at once .
老乔里恩立刻警觉起来。 |
| 4. | Her fears had always been on the alert for an upheaval .
她日夜提心吊胆，严防突变。 |
| 5. | The sentries were all on the alert .
哨兵们都警戒着。 |
| 6. | Knowing that danger threatened, the sentry was on the alert .
因为知道危险势将发生，这哨兵加意戒备。 |
| 7. | They were constantly on the alert not to be taken by surprise .
他们一直处于常备不懈状态以防突然袭击。 |
| 8. | The armies were constantly on the alert not to be taken by surprise .
部队一直处于警戒状态以防突然袭击。 |
| 9. | That was why he looked at the young man with a speculative frowning look, not condemning him, only wary and on the alert .
他所以要蹙着眉头，带着探索的神情望着这个年青人，对他存着戒心，而不斥责他，也就是这个道理。 |
| 10. | Troops are on the alert against any possible aggression
军队戒备着可能的来犯。 |
