A:did I shout…that he turned
B:I shouted…did he turn
C:did I shouted…he did turn
D:I was shouting…he had turned
如图,点E为矩形ABCD中AD边中点,将矩形ABCD沿CE折叠,使点D落在矩形内部的点F处,延长CF交AB于点G,连接AF
已知F1,F2是双曲线E x2a2−y2b2=1 的左,右焦点,点M在E上,M F1与 x 轴垂直,sin ∠MF2F1=13 ,则E的离心率为( )
When I got to school, I realized I ______ my backpack at home.