题目

Kate       on her now novel，which is supposed to come out next month．    A．has been working     B．had worked       C．will be working     D．was working 答案：A4．已知向量$\overrightarrow{AB}$，$\overrightarrow{AC}$夹角为120°，|$\overrightarrow{AB}$|=5，|$\overrightarrow{AC}$|=2，$\overrightarrow{AP}$=$\overrightarrow{AB}$+λ$\overrightarrow{AC}$，若$\overrightarrow{AP}$⊥$\overrightarrow{BC}$，则λ=$\frac{10}{3}$．