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
某单位准备和一个体车主或一国营出租车公司中的一家签订月租车合同,设汽车每月行驶x千米,个体车主收费y1元,国营出租车公司收费为y2元,观察下列图象可知,当x____ 时,选用个体车较合算