—Three times a day.
A:might
B:should
C:might not
D:should not
设F1,F2.分别是双曲线x2a2-y2b2=1a>0,b>0的左,右焦点,若在双曲线右支上存在点P,满足|PF2|=|F1F2|,且F2到直线PF1的距离等于双曲线的实轴长,则该双曲线的渐近线方程为( )
She says that she'll have to close the shop _______ business improves.