A:b>a
B:a3+b3<0
C:a2﹣b2<0
D:b+a>0
—We will build a subway in Fuzhou before 2014.
—Wow, ______! Will it pass our place?
— . You should prepare for your math exam.
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在等腰直角三角形ABC中,AB=AC=4,点P是边AB边上异于AB的一点,光线从点P出发,经BC,CA反射后又回到点P(如图),若光线QR经过△ABC的重心,则AP等于( )