设P₁表示基金经理正确地预测到牛市的概率，P₂表示基金经理正确地预测到熊市的概率，成功概率的计算公式为：( )。

A．成功概率=P₁+P₂

B．成功概率=1-P₁-P₂

C．成功概率=P₁×P₂

D．成功概率=P₁+P₂-1

Jenny went into the room, took off her coat and _____ down on a sofa.[ ]

A. would sit

B. was sitting

C. sat

D. had sat