某班共有40名学生，其中只有一对双胞胎，若从中一次随机抽查三位学生的作业，则这对 发布时间：2017-05-11 18:53 │ 来源：www.tikuol.com 题型：填空题 问题： 某班共有40名学生，其中只有一对双胞胎，若从中一次随机抽查三位学生的作业，则这对双胞胎的作业同时被抽中的概率是 ______．（结果用最简分数表示）
题型：填空题 阅读下面短文，请从方框中选出适当的句子填人文中的适当位置，使短文内容完整正确。 In the United States and Canada, people often invite friends for a meal or a party. 1 "Would you like to come over for dinner tonight?" "Hey, we are having a party on Friday. Can you come?" _ 2 _ either say thank you and accept (接受), or say sorry and give an excuse (借口) Sometimes, however( 然而), what people say is like invitation but which are not real invitations. For example. " 3 " "Let's get together for lunch soon."They are not real invitations because they don't talk about the date or the time. 4 To reply to this, people just say "Sure, that would be great."or " OK, thank you."_ 5 listen carefully. Is it a real invitation or is the person just being friendly?So next time you hear what is like an invitation,Here are the kinds of things people always say.To reply to an invitation,They just show that the person is trying to be friendly.Please come over for a drink sometime. 查看答案