如图，Rt△ABC的直角边BC在x轴正半轴上，斜边AC边上的中线BD反向延长线交y轴负半轴于E，反比例函数 $y=\frac{k}{x}$(x＞0)的图像经过点A，若S_△BEC=10，则k等于____．

根据短文内容从下面方框的7个选项中选出5个还原到文中，使短文意思通顺，结构完整，并将其答案的序号填到相应位置。
Dear Zhang Wei,
   I'm in New York now.____ . My English teacher is good-looking. Everyone in our class likes her very much.
____ . They are Sara, Ben, Nick and Peter. Sara has long straight hair.____ Ben has short curly hair and he can speak French very well, because his mother is a Frenchwoman. Nick and Peter are twins (双胞胎). ____. They can sing well.
What about your school life?____ .
                                                                                                                                                             Yours,
                                                                                                                                                             He Bin

如图所示，夏天的早晨，植物叶上常会有露珠，透过露珠看叶子，叶脉会变大、变清晰，这是因为露珠相当于一个“放大镜”，这时，叶脉应位于“放大镜”的（    ）