先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案。

    Everyone likes holidays,because they can do what they want to．The May Day holiday is coming.The students in1class are making the holiday plans.Here are2of them．

    Li Darning，the monitor of my class，is going to have a3with his parents in the city park．He says many people would like to go to the park4May Day．He can help clean the park after5picnic．Wang Lingling always works hard．She's going to have a rest at home first and then see her grandparents．Zhao Dan6he's going to Beijing to visit the Summer Palace and the Great Wall．He thinks it'll be busy7good fun．As for me．I'm going to enjoy8too．I'm going to Qingdao to9my holiday．Qingdao is a coastal(沿海的)city．There's a lot to see and to do there．I think I can have a good time there．

    What's your10for the coming May Day holiday?

如果表中某一时刻停车场剩余停车位数低于总车位数的10%，那么当车主驱车抵达单位附近时，该公司将会向车主发出停车场饱和警报．

（Ⅰ）假设某车主在以上六个时刻抵达单位附近的可能性相同，求他收到甲停车场饱和警报的概率；

（Ⅱ）从这六个时刻中任选一个时刻，求甲停车场比乙停车场剩余车位数少的概率；

（Ⅲ）当停车场乙发出饱和警报时，求停车场甲也发出饱和警报的概率．

如图所示，把重力为600N的物体匀速推到斜面顶端，斜面长为3m，高为0.9m，实际推力为300N，那么物体与斜面之间的摩擦力是____N，斜面的机械效率是____．

I am busy ________ English in my room.