题目

Like many other small boys, I was fascinated by cars, especially because my oldest brother was a bit of a car guy and subscribed to cool magazines like Car and Driver and Motor Trend. Every so often, one of those magazines would run an article on the “Car of the Future”. They featured unconventional things like small nuclear reactors as power sources. Yet, frankly, my car doesn’t do anything that my brother’s Studebaker didn’t do. It goes, it stops, it burns gasoline. I still have to steer it, and it still runs into things if I don’t steer it carefully. But guess what? All 某些植物的花汁可作酸碱指示剂。取三种花汁用稀酸溶液或稀碱溶液检验，颜色如下：花种类花汁在酒精(中性)中颜色花汁在稀酸中颜色花汁在稀碱中颜色玫瑰花粉红粉红绿万寿菊花黄黄黄大红花粉红橙绿试回答下列问题：   为试验生活中的食盐水、肥皂水、汽水、石灰水四种物质的酸碱性，我选择         花汁，不选用其他花汁的原因是                                              。