题目

阅读理解 A popular saying goes, “Sticks and stones may break my bones, but words will never hurt me.” However, that's not really true. Words have the power to build us up or tear us down. It doesn't matter if the words come from someone else or ourselves— the positive and negative effects are just as lasting. We all talk to ourselves sometimes. We're usually too embarrassed to admit it, though. In fact, we really shouldn't be because more and more experts believe talking to ourselves out loud is a healthy habit. This “self-talk” helps us motivate ourselves, remember things, solve17．下列物理量中，属于标量的是（　　）A．加速度B．瞬时速率C．平均速度D．位移