在实体属性中，可用于区别实体集合中不同个体的属性或几个属性的组合，称 ______。

阅读理解。

    This dog was born on Christmas Eve in 2002. He was different from other dogs because he was

born with only two legs. The poor dog of course could not walk and even his mother Sarah did not

want him. His first owner Michael Johnson also did not think that he could survive and he was thinking

of killing him. But then, his present owner, Jude Stringfellow, met him and wanted to take care of him.

She decided to teach and train this little dog to walk by himself. She called him "Faith".

     In the beginning, she put Faith on a surfboard (滑板) to let him feel the movement… Later she used

peanut butter on a spoon as a lure (诱惑) and reward for him for standing up and jumping around. Even

the other dog at home encouraged him to walk. Amazingly, after only six months, Faith learned to balance on his legs and jump to move forward. After further training in this snow, he could now walk like a person.

     Faith loves to walk around now. Wherever he goes, he attracts people's attention. He is fast becoming

famous on the international scene and has appeared on various newspapers and TV shows. A book named With a Little Faith is now being published about him. He was even considered to appear in one of

Harry Potter movies.

     Jude Stringfellow, his present owner, has stopped working and plans to take him around the world to

tell people "that even without a perfect body, one can have a strong will (意志)".

     Faith is a good example of the strong will and wonder of life. In life there are always unpleasant things. So, in order to feel better, you just need to look at life from another direction. I hope this message will

bring fresh new ways of thinking to everyone and that everyone will appreciate and be thankful for each

beautiful day.

1. Faith is different from other dogs because _______.

A. he doesn't have a tail

B. he has only two legs

C. he was born on Christmas Day

D. his mother loves him best

2. Faith's present owner is ________.

A. Sarah

B. Michael Johnson

C. Harry Potter

D. Jude Stringfellow

3. Which of the following is the correct order for Faith to learn to walk around like a person?

① jump to move forward

② train in the snow

③ feel the movement on a surfboard

④ balance on his legs

⑤ use peanut butter on a spoon as a reward

A. ③①④②⑤

B. ③⑤④①②

C. ②⑤③①④

D. ④⑤①③②

4. What can we learn from the passage?

A. Faith's mother can walk with two legs like a person.

B. If we don't have a perfect body, we can't be successful.

C. When we meet with difficulties, we should never give up.

D. When we have difficulties, we should wait for others' help.

什么是循环风？它有何危害？

时间管理是有效地运用时间，减低变动性。

（1）命名：__________________________

（2）相对分子质量为72且沸点最低的烷烃的结构简式__________________

患儿男，8岁，右小腿上端疼痛10天，伴高热，咽痛，食欲缺乏，有膝部扭伤史，体格检查：体温39.2℃，脉搏120次/分，右小腿上端红肿热，膝关节呈30°屈曲位，伸直时疼痛加重，X线片未见明显异常。

如果该疾病的急性症状得到控制，抗生素治疗

A．已无必要继续应用

B．还要继续应用3～5天

C．继续应用3周

D．继续应用1周

E．继续应用5周

F．停药观察，病情反复时再继续应用