题目

﹣Reading is a good way to pass the time on the plane． ﹣_______．I never go travelling without a book． A．You are joking  B．That's true C．I don't think so  D．It sounds like fun 答案：B2．已知椭圆$\frac{x^2}{a^2}$+$\frac{y^2}{b^2}$=1（a＞b＞0）的一个顶点为B（0，b），右焦点为F，直线BF与椭圆的另一个交点为M，且|$\overrightarrow{BF}$|=2|$\overrightarrow{FM}$|，则该椭圆离心率为$\frac{\sqrt{3}}{3}$．