Do people run the risk of getting the virus through handling or eating poultry where thereis no bird flu outbreak?
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What precautionary measures should people take when they slaughter and handle diseasedor dead birds in affected areas?
一盒子中有4只坏晶体管和6只好晶体管,在其中取二次,每次随机取一只,(取后不放回)若已知第一只取到是好的则第二只也是好的概率是 _______.
必然事件U的概率不是1。 ( )
A. 对
B. 错
若随机事件A、B相互独立,则事件A、B互斥。 ( )
A. 对
B. 错