The staff officers carefully charted the enemy's concentrations on the maps.参谋人员在地图上仔细标明敌军的集结地点。Aircraft carriers had sheltered in the secret rendezvous of the islands.一艘艘航空母舰隐蔽在岛群附近的秘密集结地。This port was the focal point of trade two centuries ago.两个世纪前这个港口是个贸易集结地。