耙斗装载机（）由车架、轮轴和弹簧碰头组成。
参考答案：台车
In April, 2009, President Hu inspected the warships in Qingdao, _____ the 60th anniversary of the founding
of the PLA Navy. [ ]
A. marking
B. marked
C. having marked
D. being marked
精馏过程中，塔顶回流比加大将使塔压（）。
A、降低
B、升高
C、不变
D、不确定
