The ANC could not afford to lower its guard until everything had been carried out.
在所有任务完成之前，非洲人国民大会丝毫不敢放松警惕。
《柯林斯英汉双解大词典》
2
One prison guard was killed when a riot broke out in the jail.
一位狱警在监狱骚乱中遇难。
《牛津词典》
3
As soon as they had let the fowls out, in the early summer mornings, they had to take their guns and keep guard; and then again as soon as evening began to mellow, they must go once more.