Everyone, rich or poor, can have happiness. You don't need to think too much about those 1 people. They may always feel lonely (孤独的) 2 their houses are too big, and they may want to take a 3 on country roads because they drive to work every day in the busy city.

    4, happiness is always around you. When you are unhappy, your friends will come to   5 you and this will make you happy. When you study hard at your lessons, you will get good marks and of course you will 6 happy about it. If you don't feel 7, your parents will take good care of you and you will be happy. When you are 8, you can also say you are happy because you may have something else that money can't buy. When you 9 problems, say loudly that you are happy because you have 10 chances to challenge (挑战) yourself. Then you can succeed (成功) in what you do and this may bring you happiness.

如果两个三角形全等，那么下列结论不一定正确的是（   ）

已知函数$\left\{\begin{array}{c}x+k\left(1-a^2\right),\left(x\ge 0\right)\\ x^2-4x+{\left(3-a\right)}^2,\left(x<0\right)\end{array}\right.$，其中a∈R．若对任意的非零实数x₁，存在唯一的非零实数x₂（x₁≠x₂），使得f（x₁）=f（x₂）成立，则k的取值范围为（　　）

水平桌面上放置甲乙两个完全相同的杯子，杯中分别盛有不同浓度的盐水，将同一个鸡蛋先后放入其中，当鸡蛋静止时，两个杯子中液面恰好相平，鸡蛋所处的位置如图所示，则（   ）