题目

10张奖券中只有3张有奖，5个人购买，至少有1人中奖的概率是(    )A.               B.                C.                 D. 答案：解析：先求无人中奖的概率，=,∴ 至少有1人中奖的概率是.答案：D— Is your mother a teacher?— Yes, she is. She ________ at a junior high school.A.taughtB.teachesC.will teachD.is teaching