We usually __________ to school by bike, but she __________ to school on foot.
A:go; goes
B:go; go
C:goes; goes
D:goes; go
(2015•苏州)通过下列图示实验得出的结论中正确的是( )
最近科学家获得了极具理论研究价值的N4分子。有关N4说法正确的是( )
(Ⅰ)证明:AC是圆O的切线;
(Ⅱ)设AC与圆O的切点为F,求证:EF∥AO.