A:what she is going to do next
B:what was she going to do next
C:what is she going to do next
D:what she was going to do next
我们的生活 离不开朋友( )
下表是一个正常人的血浆、原尿和尿液的检验结果(“√”表示含有,“×”表示不含有),请判断O、P、Q分别代表的物质是( )
物质
血浆
原尿
尿液
O
√
×
P
Q
在椭圆x2a2+y2b2=1a>b中,记左焦点为F,右顶点为A,短轴上方的端点为B,若∠BFA=30°,则椭圆的离心率为( )