在一次百米比赛中，甲，乙等6名同学采用随机抽签的方式决定各自的跑道，跑道编号为1至6，每人一条跑道

（Ⅰ）求甲在1或2跑道且乙不在5或6跑道的概率；

（Ⅱ）求甲乙之间恰好间隔两人的概率．

 根据短文内容，用方框中所给单词的正确形式填空，使短文通顺，完整，每词限用一次。

  Nowadays, there are many robots working in factories. They can help to build cars, and____  doing simple jobs over and over again. Fewer people will do such jobs in the future because they are boring, but robots will never get ____ . Some robots in Japan can walk and dance. There will be a lot____ robots in future. Some scientists believe that we can make robots move like a human and also it will be possible to make____  really think and talk like a human.. However, it may take ____  of years. The robots in the future will have many different shapes, such as humans, plants, animals and so on. Do you think you will have your own robot in the future

①聚乙烯和乙烯②甲醛和葡萄糖③淀粉和纤维素④蔗糖和麦芽糖⑤聚乙烯和聚氯乙烯．

世界最高峰珠穆朗玛峰海拔8844米，我国陆地最低的吐鲁番盆地在海平面以下155米，两地相对高度是 （   ）

关于摩擦力，下列说法正确的是（　　）