That's where Filch has been keeping guard, Ron muttered.

费尔奇一直在这里站岗。罗恩小声说。

While two detectives were keeping guard at the door, two others opened the parcel.

这时两个侦探把住门口，另外两个侦探打开了包裹。

The DPRK is in the midst of recovering from three typhoons in the past months while keeping its guard up against COVID-19.

几个月前，三次台风袭击朝鲜，朝鲜正处于恢复当中，一边对新冠肺炎保持警惕。