由匀速直线运动公式V=$\frac{s}{t}$​可知，匀速直线运动的速度（　　）

 阅读理解。根据短文，判断正误。

      There are two picturesabout our city. One is now. the other one is before(以前的). Look! There was a small park, but now there is a big and beautiful park. And there is a lake with some ducks on it. There wasn't a lake before. In our city there were some old houses, small trees. But now there are some new and high buildings（建筑物）. The trees are very tall and the flowers are very beautiful. There are some supermarkets and some cars now. I love my city. Do you want to visit here?

如图：二次函数y=ax2+bx+c的图像所示，下列结论中：①abc＞0；②2a+b=0；③当m≠1时，a+b＞am²+bm；④a﹣b+c＞0；⑤若ax₁²+bx₁=ax₂²+bx₂，且x₁≠x₂，则x₁+x₂=2，正确的个数为（   ）