Tom is the son of a farm owner. One New Year's Day, when he was 15, his father asked him (work) on the farm for one year when he was free. Tom was unhappy with his (father) idea. "That isn't my job. I have too schoolwork to do." Hearing this, his father said, " I promise to give you the best present you can finish one year's work." Tom thought for a while and agreed.
Starting one Saturday, boy got up early and worked hard until evening, just like any other farmer. Time (pass) quickly. Tom's crops grew well. the last day of the year, the father called his son to him. "I'm happy to see that you have worked very hard the whole year," said the father. "Now, tell me you want."
The boy smiled and showed his father a big piece of bread (make) of his wheat (小麦). "I have already got the (good) present: No pain, no gain. I think this is what you wanted me to know." His father was pleased to hear that.

,
,
是三角形
的三边,并且满足等式
,试确定三角形
的形状
,
)求:
;
| 温度/℃ | 20 | 40 |
| 硝酸钾溶解度/g | 31.6 | 63.9 |

B .
C .
D .
,则⊙O的半径为.
If you have no special plans for your holidays, why not spend your time helping others?
Don't listen to people who say the young people today often think only of themselves. It's not true at all. More and more people in the USA volunteer(自愿)to spend their school holidays working for others. And they don't do it for money. Here are some of their stories.
Alice Hamilton, 17
I'm going to help the Forest Centre build new hiking paths in the mountains. It's going to be terrific—I'll spend the whole summer living in the tent and breathing the clean mountain air. I'm going to sleep under the stars. It'll be a nice sport, and I'll be able to do something good at the same time.
Jason Moore, 18
This summer, I'm going to volunteer with Special House Program. They build good, low-cost houses and sell them to families that are not very rich. They'll teach me what to do, so I'll help people and also have a chance to learn how to build houses.
Trish Anderson, 16
I'm going to teach kids who have trouble reading. I'll work for a program called “Reading for Life”. Every day, I'm going to help kids choose and read books that they like. I want to be a teacher and I love children and reading, so this is going to be a great experience for me.
,过y1上的任意一点A作x轴的平行线交y2于点B,交y轴于点C,如果
=2,那么y1的函数表达式是 .
