同等压力等级的阀门比较，（）重量最轻。A.截止阀 B.减压阀 C.针形阀

Have you ever seen a movie called “ The Choir Boys”(《放牛班的春天》)？The French movie tells the story of a group of naughty boys who learn music from a dedicated(尽职的) teacher. In Shanghai, there is also a group of children learning music. But their story is a bit different.

The musical group, “Shepherds’ Kids” , was founded(建立) by the Shanghai Jiuqian Volunteer Center. There are about 40 students in this group. Their parents are migrants(打工者) working in Shanghai.

“ The music courses are free,” said Zhang Yichao, founder of the group. “We just want to make the children’s lives more colorful.”

The kids learn singing, dancing and musical instruments. Their teachers are volunteers from high schools.

Learning music is not an easy job, especially for these migrant workers’ children.

“I never know the musical stave(五线谱) before,” said Hua Delong, 13. “Sometimes it was really hard to study.”

Tang Yue is a volunteer teacher at the center. She is a student from Shanghai Ping’he Bilingual High School.

“These kids face difficulties bravely,” said Tang. “Sometimes they have to help their parents do housework and have little time to practice, but I never hear them complain.”

Their hard work has paid off(回报). Today many people know the group. They have even performed as a choir for foreign pop stars.

Li Luo, 14, told “ Teens” how appreciative she was of the group.

“I had little fun before. I seldom(很少) watched TV. Study seemed the most interesting thing in my life. “Shepherds’ Kids has given me a new life.”

小题1:In Hua Delong’s opinion, learning music is not an easy job because _______.

A．he didn’t know the musical stave before

B．he had little fun before

C．the music courses are not free

D．he seldom watched TV before小题2:From the story we can know that ______.

A．the naughty boys were successful at last

B．the “Shepherds’ Kids” has made great success

C．all the volunteers giving lessons for the children are music teachers

D．the children learnt music very easily小题3: The story is an introduction of ______.

A．the French movie “The Choir Boys”

B．a musical group “The Shepherds’ Kids”

C．the foundation of “The Shepherds’ Kids”

D．the children learning music

下颌骨髁突骨折颌间固定最佳保持时间是（）

A.1～2周

B.2～3周

C.3～4周

D.4～5周

E.5周以上

下列物理量不属于矢量的是（）

A．瞬时速度

B．重力

C．体积

D．加速度

亚里士多德最大的哲学贡献是（）

A.创立逻辑学

B.批判柏拉图的理念论

C.提出了哲学产生的三个条件

D.意识到人类认识自己的重要性

软件的易维护性是指理解、改正、改进软件的难易程度。通常影响软件易维护性的因素有易理解性、易修改性和 (7) 。在软件的开发过程中往往采取各种措施来提高软件的易维护性。如采用 (8) 有助于提高软件的易理解性； (9) 有助于提高软件的易修改性。在软件质量特性中， (10) 是指在规定的一段时间和条件下，与软件维持其性能水平的能力有关的一组属性； (11) 是指防止对程序及数据的非授权访问的能力。

（11）处填（）。

A．安全性

B．适应性

C．灵活性

D．容错性