—Guess what? I happened to have met Mark at the party last week.
—If my memory serves me correctly, you two ________ each other for almost ten years.
A:haven't seen
B:hadn't seen
C:didn't see
D:don't see
(-x+y)( )=x2-y2,其中括号内的是( )
请从下列选项中为下边漫画选择一个最恰当的主题:( )
在Rt△ABC中,∠C=90°,a=4,b=3,则sinA的值是 ( )