1. He noticed at once that discipline was slack.
    他马上觉察到敌方纪律松弛.

2. He noticed at once that discipline was slack: the Danes had the self-confidence of conquerors, and their security precautions were casual.
    他马上发现丹麦军纪律松弛，他们以征服者自居，安全措施马马虎虎。