该竞赛分为预赛和决赛两个阶段,参加决赛的队伍按照抽签方式决定出场顺序.通过预赛,选拔出甲、乙等五支队伍参加决赛.(Ⅰ)求决赛中甲、乙两支队伍恰好排在前两位的概率;(Ⅱ)若决赛中甲队和乙队之间间隔的队伍数记为X,求X的分布列和数学期望.
【简答题】句型转换。1.Ilikeelephantsbecausetheyarefriendly.(对划线部分提问) ________youlikeelephants? 2. Mymotherlikespandasverymuch.(对划线部分提问) ________doesyourmotherlikeverymuch? 3.Ilikedogs.Theyareinteresting. (合并为一句) Ili...
【单选题】There is only one ticket for Lucy and Susan. So ______ of them will go to the movie.
【单选题】Maria is _____ geography, but she can get better results if she does her best. [ ]