皮皮学，免费搜题
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【简答题】
为贯彻“激情工作，快乐生活”的理念，某单位在工作之余举行趣味知识有奖竞赛，比赛分初赛和决赛两部分．为了增加节目的趣味性，初赛采用选手选一题答一题的方式进行，每位选手最多有5次选题答题的机会，选手累计答对3题或答错3题即终止其初赛的比赛，答对3题者直接进入决赛，答错3题者则被淘汰．已知选手甲答题的正确率为 . (1)求选手甲答题次数不超过4次可进入决赛的概率； (2)设选手甲在初赛中答题的个数为 X ，试写出 X 的分布列，并求 X 的数学期望．
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举一反三
【单选题】The ______ news made all the people at the party _____.
A.
frightening; frightening
B.
frightening; frightened
C.
frightened; frightening
D.
frightened; frightened
【单选题】The little boy was ____by the ____ sound. [ ]
A.
to frighten; frightening
B.
frightened; frightening
C.
frightened; fright
D.
frightening; fright
【单选题】The __________ girl sat in the corner, __________. [ ]
A.
frightening; crying
B.
frightening; cried
C.
frightened; crying
D.
frightened; to cry
【单选题】They are ______ at the _______ news.
A.
frightening, frighten
B.
frightened, frightening
C.
frightening, frightening
D.
frightened, frightened
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