【单选题】I send my boys to a good public school so that they will meet people who ______________ useful to them later on.
【简答题】Hello, everyone! My name is Tony. Welcome to our school lost and found 1 . You can always 2 some books or other things somewhere in the school because of some careless ( 粗心的 ) students. Some students ...
【简答题】有甲、乙两个班级进行数学考试,按照大于等于85分为优秀,85分以下为非优秀统计成绩后,得到如下的列联表: 优秀 非优秀 总计] 甲班 10 乙班 30 合计 105 已知在全部105人中随机抽取1人为优秀的概率为 2 7 , (1)请完成上面的列联表; (2)根据列联表的数据,能否在犯错误的概率不超过5%的情况下,认为“成绩与班级有关系”. 附:临界值表 P(K 2 ≥k 0 ) 0.10 0.0...
【简答题】根据句意及首字母提示完成单词。 1. Drinking milk every day is good for our h_____. 2. A lot of v_____ make us keep in good health. 3. On Valentine's Day (情人节) boys often send c_____ to their girlfriends. 4. J_____ fo...
【简答题】如图,为了测量河宽,某同学采用的办法是:在河的对岸选取一点A,在河的这岸选一点B,使AB与河的边沿垂直,然后在AB的延长线上取一点C,并量得BC=30米;然后又在河的这边取一点D,并量得BD=20米;最后在射线AD上取一点E,使得CE ∥ BD.按照这种做法,她能根据已有的数据求出河宽AB吗?若能,请求出河宽AB;若不能,她还必须测量哪一条线段的长?假设这条线段的长是m米,请你用含m的代数式表示河...
【判断题】( ).开始攻丝时,应先用二锥起攻,然后用头锥整形。