题目

The plane arrived. Some of the detectives were waiting inside the main building.Others were waiting on the airfield. （用连词或关系词把两个句子合并） 答案：When the plane arrived, some of the detectives were waiting inside the main building, while others were waiting on the airfield.将一个圆柱体A分别竖直放在水和液体甲中，都能漂浮，并且分别有和的体积露出液面。 （1）这两种情况下，圆柱体A下表面所受液体压强之比为多少? （2）如图，现有一个左右力臂之比为3:1的轻质杠杆。用细线将圆柱体A悬挂在杠杆左端并放入液体甲中，再用细线在杠杆右端悬挂一个完全相同的圆柱体B并放在水平地面上，当杠杆两端细线均被拉直且平平衡时，圆柱体A有的体积露出液面，且该圆柱体底面所受液体压强为800Pa。求此时圆柱体B对地面的压强为多少? 请在图中画出圆柱体A的受力示意图。