While two detectives were keeping guard at the door请问这里的guard at the door是固定搭配吗?

While two detectives were keeping guard at the door请问这里的guard at the door是固定搭配吗? While two detectives were keeping guard at the door.分析一下此句中keep的用法,guard在句中是动词吗? When the plane arrived,some of the detectives were waiting inside the main building while others were waiting on the airfield.这里的While是什么意思?或者在句子中充当什么成分?While two detectives were keeping guard at the door,two o 一个句子中有动词前面什么情况下要用be动词?例如下面的句子：while two detectives were keeping guard at the door.two other detectives opened the parcel,前面半句用了BE动词,与KEEP购进过去进行时,后面半句为什 When the plane arrived,some of the detectives were waiting inside the main building while .后面用个some detectives可以不?后面用while什么意思? 求以下英语句子的成分分析,最好说出是什么种类和句型1.Two men took the parcel off the plane and carried it into the Customs House.2.While two detectives were keeping guard at the door,two others opened the parcel.3.To surprise,th 哪个是主句,哪个是从句When the plane arrived,some of the detectives were waiting inside the main building while ohers were waiting on the airfield. While others were waiting on the airfield中WHILE是什么意思呢?这句话的前面还有一句When the plane arrived,some of the detectives were waiting inside the main building。WHILE。 often police detectives是什么意思 英语翻译1What was happening when two of the detectives opened the parcel?2What was happening when the plane arrived? two detectives carried it into the Customs House中得carried it该怎么读,读快了总感有点不顺 When the plane arrived,some of the detectives were waiting inside the main building while others were waiting on the airfield这里有两个当.时候（when和while）是怎么回事 翻译一下句子,快点谢谢诶Detectives were waiting at the airport all morning.They were expecting a valuable parcel of diamonds from South Africa.Two men took the parcel of the plane.Two detectives opened it.The parcel was full of stones and s inside the building和in the building意思一样吗?when the plane arrived,some of the detectives were waiting inside the main building,while others were waiting on the airfield.some of the detectives were waiting inside the main building可以改 有关while 用法while two defectives were keeping guard at the door ,two others opened the pacel.这里的WHILE可不可以换成WHEN. While two men () at the door,two others went into the house Did the detectives save the diamonds? while(!