题干
Most British people drink tea every day _______ they prefer black tea. They usually add milk or sugar to their tea.
A：so
B：or
C：but
D：and
答案(点此获取答案解析）
D
-
＝1的两个焦点，点P在双曲线上，且满足∠F1PF2＝90°，则△F1PF2的面积是( )