阅读下面的文字，根据要求作文。

       有人说，幸福是贫困中相濡以沫的一块糕饼；有人说，幸福是患难中心心相印的一个眼神；有人说，幸福是父亲一次粗糙的抚摸；有人说，幸福是母亲一声温柔的叮咛；有人说，幸福是老师一次亲切的问候和鼓励；有人说，幸福是朋友一个温馨的字条或短信。……

关于幸福，你也一定会有自己的体验与理解，或与前面的相同，或有更独特的体会。

       请以“         是幸福的”为题，写一篇不少于600字的作文。

       要求：①先把题目补充完整，然后作文。②文体自选（诗歌、戏剧除外），立意自定。③内容具体，有真情实感。④书写规范，卷面整洁。文中不得出现真实的地名、校名、人名。

如图所示，甲、乙、丙三个光滑斜面，它们的高度相同、倾角不同，θ₁＜θ₂＜θ₃．现让完全相同的物块沿斜面由静止从顶端运动到底端．关于物块沿不同斜面运动时重力做功W和重力做功的平均功率P，下列说法正确的是（   ）

    Most people have jobs. They go to 1 nearly every day. Some people are lucky. Either they have very interesting jobs or they earn a lot of 2. Most people are not so lucky. Either their jobs are a bit 3 or they don't get well 4.

    The most interesting jobs are often the most 5. People spend long time learning how to do them. Doctors study for 6 six years after finishing school. Airline pilots(飞行员) study longer. They have to learn to fly small airy craft first, and then 7 move up to bigger and bigger aircraft. Most airline pilots are at least 30 years old.

    Some 8 people have interesting and well-paid jobs. Many successful athletes(运动员) are usually under 35. Older people usually can't 9 these sports very well because they can't move fast enough.

    Most people work until they are 60 or 65 year old. Some people 10 retire. These people usually have very interesting jobs. Writers, artists, musicians and actors usually work until they die.