阅读理解

Found

A set of keys. There is a toy bear on it, too.  If you lose it, call me at 880-1167313.  I'm from No. 2 Middle School.

                                                                                            Jack  Lost

An old bike.  It's black with a plastic(塑料的)basket.  Its seat is yellow.  If you find it, please return it to me.  I live in the fifth floor in Building 2.

    Miller   Lost

Yesterday, I lost a novel written by Mo Yan.  Its name is Frog.  I’m eager(渴望的)to find it.  If you find it somewhere, can you return it to me? I’m from Class 6, Grade 7.

                                               Louis

微生物的种类繁多。艾滋病是由下列哪种微生物引起的（　　）

读图回答

如图，已知点A是第一象限内横坐标为2 $\sqrt{3}$ 的一个定点，AC⊥x轴于点M，交直线y=﹣x于点N．若点P是线段ON上的一个动点，∠APB=30°，BA⊥PA，则点P在线段ON上运动时，A点不变，B点随之运动．求当点P从点O运动到点N时，点B运动的路径长是____．