C

    Waste can be seen everywhere in the school. Some students ask for more food than they can eat and others often forget to turn off the lights when they leave the classroom. They say they can afford these things. But I don't agree with them.

    Waste can bring a lot of problems. Although China is rich in some resources, we are short of others, for example, fresh water. It is reported that we will have no coal or oil to use in 100 years. So if we go on wasting our resources, what can we use in the future and where can we move? Think about it. I think we should say no to the students who waste things every day. Everybody should stop wasting as soon as possible.

    In our everyday life, we can do many things to prevent waste from happening, for example, turn off the water taps when we finish washing, turn off the lights when we leave the classroom, try not to order more food than we need, and so on. Little by little, everything will be changed. Waste can be stopped one day, if we do our best.

2017年3月1日，最高人民法院发布了新修订的《最高人民法院关于公布失信被执行人名单信息的若干规定》。其中明确，被执行人为未成年人的，人民法院不得将其纳入失信被执行人名单。这一规定，体现了对未成年人的（    ）

如图所示，定滑轮重1N，动滑轮重1N。物体A在拉力F的作用下，1s内将重为8N的物体A沿竖直方向匀速提高了0.3m．如果不计绳重和摩擦，则以下计算结果不正确的是（）