以O 为支点质量忽略不计的杠杆挂上10N 重物A，F _A为作用在杠杆上的力，杠杆同时还受另一个大小与F _A 不等、竖直向上的力F _B 作用，处于平衡。在图12中画出F _B的示意图并标示它的大小。

如图，抛物线C₁：y=x²+bx+c经过原点，与x轴的另一个交点为（2，0），将抛物线C₁向右平移m（m＞0）个单位得到抛物线C₂，C₂交x轴于A，B两点（点A在点B的左边），交y轴于点C．

    Sometimes we feel good, such as when we get good grades or when something good happens. Sometimes we feel bad, such as when we argue with our classmates or when the teachers criticize us. Both kinds of feelings are common. Of course, we all enjoy good feelings, but when we feel unhappy, sometimes we don't know what to do about it. Here is a plan that will help you when your feelings are bothering you.

    ⒈ACCEPT your feelings. Say to yourself, “I am sad.” “I am seared.” “I am angry.” “I am embarrassed.” It's all right to have these feelings.

    ⒉RELAX and have a rest before you act. Take slow deep breaths (呼吸)and relax your body. Imagine that you are in a safe place. You can listen to some music or sing a beautiful song!

    ⒊THINK about ways to help yourself. Thinking helps you do something smart instead of hurting yourself or making things worse.

    ⒋DO something to help yourself. Maybe you can talk to someone, or do something you enjoy. If it doesn't work, go back to Step3.