【单选题】已知向量a=(1,y),b=(x,4),若a∥6,则xy的值为( )
【多选题】阿司匹林的性质与下列叙述中 _______ 相符。
【单选题】凸轮轴的磨损和弯曲将使气门的最大开度和充气效率
【单选题】Pardon? I did not hear you clearly -______________.
A.
Sorry, I will repeat it.
B.
you didn’t listen to me carefully
【单选题】已知a b=(6,1),若a∥b,则 ( )
【简答题】已知全集U={x|1≤x≤9,x∈Z},A={1,2,4,8},B={3,4,6,9},C={3,6,8},求(A∩B)∩C,(C ∪ A)∩(C ∪ B).
【单选题】he is a new manager. He__to make a presentation in the meeting