光在真空中的传播速度最______，其速度值为______m/s．

It is only 　　　　 people know the importance of science 　　　　 science can really serve the people.

A．that； when

B．when； that

C．then； that

D．that； then

假如物体间的摩擦力突然消失，下列哪些现象是不可能的(    )

A．静止在水平公路上的汽车无法开动

B．我们将无法写字，因为笔会从手中滑下来

C．静止在水平公路上的汽车很容易开动

D．我们将无法系上鞋带

阅读理解。

     There are some very good things about open education. This way of teaching allows the students to

grow as people, and to develop their own interests in many subjects. Open education allows students to

be responsible for their own education, as they are responsible for what they do in life. Some students do

badly in a traditional classroom. The open classroom may allow them to enjoy learning. Some students

will be happier in an open education school. They will not have to worry about grades or rules. For

students who worry about these things a lot, it is a good idea to be in an open classroom.

     But many students will not do well in an open classroom. For some students, there are too few rules.

These students will do little in school. They will not make good use of open education. Because open

education is so different from traditional education, these students may have a problem getting used to

making so many choices. For many students it is important to have some rules in the classroom. They

worry about the rules even when there are no rules. Even a few rules will help this kind of students. The

last point about open education is that some traditional teachers do not like it. Many teachers do not

believe in open education. Teachers who want to have an open classroom may have many problems

at their schools.

     You now know what open education is. Some of its good points and bad points have been explained. You may have your own opinion about open education. The writer thinks that open education is a good

idea, but only in theory. In actual fact, it may not work very well in a real class or school. The writer

believes that most students, but of course not all students, want some structure in their classes. They want

and need to have rules. In some cases, they must be made to study some subjects. Many students are

pleased to find subjects they have to study interesting. They would not study those subjects if they did not have to.

1. Open education allows the students to __________.

A．grow as the educated

B．be responsible for their future

C．develop their own interests

D．discover subjects outside class

2. Open education may be a good idea for the students who __________.

A．enjoy learning

B．worry about grades

C．do well in a traditional classroom

D．are responsible for what they do in life.

3. Some students will do little in an open classroom because __________.

A．there are too few rules

B．they hate activities

C．open education is similar to the traditional education

D．they worry about the rules

4. Which of the following best summarizes the passage?

A．Open education is a really complex idea.

B．Open education is better than traditional education.

C．Teachers dislike open education.

D．The writer thinks that open education is a good idea in practice.

45岁女性，乳晕下发现一小硬结， * * 偶尔有少量溢液，超声示囊性管腔内见一突出新生物，该病最可能的诊断为（）

A.导管内原位癌

B.外周型导管内 * * 状瘤

C.积乳囊肿

D.纤维囊性病

E.中央型导管内 * * 状瘤

正确利用情报的思维基础是（）。