Police were on guard at Barnet town hall.

警察在巴内特市政厅内时刻保持警惕

Police were on guard at Barnet town hall.

警察在巴尼特市政厅值守。

At the outset, it seemed necessary to be on guard against the other two.

一开始，似乎有必要提防另外两个。

Two soldiers must be on guard all night.

两名战士必须通宵警戒。

But bid true knowledge stand on guard.

但要吩咐真知识看守着门口。

Two soldiers must be on guard all night.

必须有两个士兵整夜站岗。