在运动场上进行百米赛跑,当发令枪响时,运动员立即向前冲出,在此过程中,人体参与接受信息的器官主要是 ( )
A:眼
B:耳
C:脑和脊髓
D:神经
已知函数y=x2+1,x≤0-2x,x>0 ,使函数值为5的x的值是( )
-- Would you like to play football after school?
-- ________. I have a lot of homework to do.