在平面直角坐标系中,抛物线y=x2-1与y轴的交点坐标是______.
把x=0代入y=x2-1中,得y=-1,
∴抛物线y轴的交点坐标(0,-1).
故本题答案为(0,-1).
— What do you think of Mary’s dress?
— I think it still looks quite fashionable on her it is a style of many years ago.
A.though
B.unless
C.until
D.because
钻孔灌注桩施工时,护筒内径宜比桩径大()
A.100~200mm
B.200~300mm
C.200~400mm
D.300~400mm