A:x2+4x﹣5
B:x2+8x+7
C:x2+2x﹣3
D:x2+6x﹣10
Thanks for your invitation, but I'm so sorry I can't go. I need to _________ my baby at home.
根据达尔文的进化学说,长颈鹿的颈和腿之所以特别长,是由于( )