一Excuse me, but where's Mrs. Liu? I want to ask her for some advice. 一She the library. You can find her there.
A:has been to
B:has gone to
C:was in
D:went to
按拼音写汉字
dīng
hài
jiān
____住
厉____
____视
xiàng
xīng
shuǎi
气____
卫____
____掉
22=1+12+2;32=2+22+3;42=3+32+4;52=4+42+5;…
已知椭圆和双曲线焦点F1,F2相同,且离心率互为倒数,P是椭圆和双曲线在第一象限的交点,当∠F1PF2=60°时,椭圆的离心率为( )