【单选题】Stay here, boy. Don’t go out. It now.
【单选题】--- What time do I have to leave, Dr Li? --- _________, don’t stay here ________ visiting hours.
【单选题】Is there _______ here? If not, don't stay here alone. [ ]
【单选题】Pushing sequence of a stack is {1,2, ⋯ ,n } .If the second number of popping sequence is 2,then how many possible choices are there for the first one?
【简答题】Stay here, boy. Don't go out.It _____(rain) now.
【单选题】Pushing sequence of a stack is {1,2, ⋯ ,n } .If the second number of popping sequence is n,then how many possible choices are there for the first one?
【单选题】Is there _____ here? If not, don't stay here alone. [ ]
【单选题】Pushing sequence is {1,2, ⋯ ,100}.In popping sequence,before 10,there are four numbers larger than 10 .Which one cannot be popped out before 10.
【简答题】设随机变量X1, X2相互独立,且X1服从二项分布B(20, 0.7);X2服从l=3 的泊松分布P(3)。记Y=X1-2X2+2,则E(Y )=__________;D(Y )=_________。