由 $K^2=\frac{n{\left(ad-bc\right)}^2}{\left(a+b\right)\left(c+d\right)\left(a+c\right)\left(b+d\right)}$ 计算得 $k=\frac{110{\left(40\times 30-20\times 20\right)}^2}{60\times 50\times 60\times 50}\approx 7.822$

附表：

参照附表，得到的正确结论是(   )

    On December 14，2017，we were sorry to hear that Yu Guangzhong, a famous poet died of illness in Taiwan. He was born in Nanjing in 1928. His mother's hometown is in Wujin，Changzhou. So he called himself a southern person.

    Later, he went to Taiwan. In 1952 he graduated from Taiwan University. Then he graduated from University of LOWA in 1959. He taught at Soochow University, Normal University, Taiwan University , and Chengchi University. He got a lot of prizes in literature(文学)，such as.Wu San lien Literature Prize, China Times Award, Golden Tripod，National Arts Award and all the major(主要的)Awards in Taiwan. He is famous both in Taiwan and in Mainland.

    He was in Taiwan, but he always missed his hometown in Mainland. In one of his poems Nostalgia(乡愁) ，he showed his feeling of homesickness. Let's enjoy his famous poem Nostalgia.

Nostalgia

When I was young，                   But later on,

Nostalgia was a tiny, tiny stamp.          Nostalgia was a low，low  grave.

Me on this side，                      Me on this side，

Mother on the other side.                And my mother ;inside.

When I grew up，                     And at present，

Nostalgia was a narrow boat ticket.        Nostalgia becomes a shallow strait.

Me on this side，                      Me on this side，

Bride on the other side.                  Mainland on the other side.

材料一：学而时习之，不亦说乎？
材料二：知之为知之，不知为不知。
材料三：治理国家要以德来感化人民。
请回答：（1）以上三段材料是我国古代什么时期哪位大思想家、大教育家说的？他的言论，被他的弟子编入哪部书中？
（2）指出材料三中 孔子的主要观点。
（3）他是我国古代哪一家学派的创始人？

阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。

    Many facts suggest that children are overweight (超重的) and the situation is getting worse, according to the doctors. I feel there are a number of reasons for this.

    Some people blame the fact that we are surrounded by shops selling unhealthy, fatty foods, such as fried chicken and ice cream, at low prices. This has turned out a whole generation of grown-ups who seldom cook a meal for themselves. If there were fewer of these restaurants, then probably children would buy less take-away food.

    There is another argument that blames parents for allowing their children to become overweight. I agree with this, because good eating habits begin early in life, long before children start to visit fast food shops. If children are given fried chicken and chocolate rather than healthy food, or are always allowed to choose what they eat, they will go for sweet and salty foods every time, and this will carry on throughout their lives.

    There is a third reason for this situation. Children these days take very little exercise. They do not walk to school. When they get home, they sit in front of the television or their computers and play computer games. Not only is this an unhealthy pastime (消遣), it also gives them time to eat more unhealthy food. What they need is to go outside and play active games or sports.

    The above are the main reasons for this problem, and therefore we have to encourage young people to be more active, as well as steering them away from fast food shops and bad eating habits.