题目

In the past, boredom was just part of life. You didn’t have a phone to ______ you in the car. You sat in the back seat and stared out of the window. But today, boredom is easy to ______. You can fill ______ time with apps, Xboxes and computers.In fact, being bored can get you into real _______.Boredom can lead to worry (Should I be doing something?). It can lead to bad ______ (I’ll ride my bike down the stairs --- what could go wrong?). People who are bored may ______ be more likely to abuse alcohol or drugs.According to some experts, however, it turns out boredom can be ______ for you. Wh物理就在我们身边，自行车的设计者运用了很多物理知识，下列说法中错误的是（ ）A．螺母下面垫一个垫圈，是为了增大压强B．车轴上装有滚动轴承是为了减小摩擦C．车轮的外胎做有凹凸花纹是为了增大摩擦D．尾灯可以将从不同方向射向它的光反射，然后面的人看到