【单选题】已知向量a=(1,y),b=(x,4),若a∥6,则xy的值为( )
【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
【多选题】党的十八大提出的建设社会主义生态文明的基本方针是( )
【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 ( )
【单选题】he is a new manager. He__to make a presentation in the meeting