看图读一读，判断句子正误。

    Hi, I'm Sally. On my way to school, I can see some trees, they're green and brown. I can see some clouds(云). They're white. I can see a bike. It's under the tree. It's blueand black. I can see a yellow cat, it's in the tree. I can hear a plane. I canhear a dog. I can hear a car and a bus, too.

小明同学在社团活动中给发明的机器人设置程序：（a，n），机器人执行步骤是：向正前方走a米后向左转n°，再依次执行相同程序，直至回到原点．现输入a=3，n=60°，那么机器人回到原出发点共走了____米．

如图，点A、B是反比例函数 $y=\frac{3}{x}$ （x＞0）图象上的两个点，在△AOB中，OA=OB，BD垂直于x轴，垂足为D，且AB=2BD，则△AOB的面积为____