1. Oh, I have             (忘) my key in the room, we can't open the door.
2. Though he lives alone, he has a lot of friends and doesn't feel             (孤独的).
3. Mrs. White smiled             (幸福地) when she received a present from her daughter on Mother's Day.
4. As we all have grown up, we should learn to look after             (自己).
5. Everybody knows the             (重要性) of doing exercises, but few can keep doing it.

       Happiness is for everyone. You don't   1   (需要) to care about those who are very   2  (穷困的).
Why? Because those who have big houses may often feel   3    (孤独) and those who have cars want
to   4    (走路)on country roads in their free time. 
       In fact, happiness is always around you. When you are in   5   (麻烦), your friends will help you;
when you study   6   (努力)at your lessons, your parents are   7   (照顾) good care of your life and your
health. All these are your happiness.  
      When you are not   8    (富有的)  you can also say you are very happy, because you have something else that money can't   9   (买). When you meet with problems, say   10   (大声地) that you are happy,
because you have more chances to challenge yourself.
Take every chance you get, and you can be a happy and lucky person.