问题 选择题

下列关于分子和分子热运动的说法中正确的是

A.用显微镜观察液体中悬浮微粒的布朗运动,观察到的是微粒中分子的无规则运动

B.分子a只在分子力作用下从远处由静止开始靠近固定不动的分子b,当a受到的分子力为零时,a的动能一定最大

C.气体的温度升高时,分子的热运动变得剧烈,分子的平均动能增大,撞击器壁时对器壁的作用力增大,从而气体的压强一定增大

D.当分子力表现为引力时,分子势能随分子间距离的增大而增大

答案

BD

布朗运动描述的是固体颗粒的无规则运动,反映的是液体分子的无规则运动;一定质量的理想气体的温度升高时,分子的热运动变得剧烈,分子的平均动能增大,由于不清楚体积的变化,根据气体状态方程知道气体的压强变化无法确定.

阅读理解

阅读理解诶。

     Primary teachers are responsible for guiding children through the formation of many important life skills,

and also watching over their students' social development. Primary teachers come into contact with about

30 students every day, and teach them a variety of subjects. Many hours are spent before and after class on

planning, preparation and correction. One should be a very patient, caring, yet firm person to be able to deal

with the demands of children in the four to twelve-year-old age group. Secondary teachers teach specific

subjects to various groups of students.

     Just like primary teachers, they spend an amount of time planning and preparing lessons and correcting

homework-their duties are not restricted to face-to-face teaching. Dealing with twelve to eighteen-year-olds

requires a wide range of skills. If you become a primary teacher, you will need to decide whether to be a

"generalist" (多面手), teaching a wide range of subjects, or a "specialist", teaching only one or two. Most

primary teachers are specialists. Generalist teachers spend the greatest part of their day with one class, which

means that they spend more time with the same children. Specialist teachers have more time away from their

students. It is therefore very important for generalist teachers to develop a strong working relationship with

their students. The unique rapport (和谐) you can develop with a particular set of students is one of teaching's

greatest pleasures. However, the disadvantage of primary teaching is that if you have a difficult student, you

will be forced to deal with him or her, all day, every day, throughout the school year. Teachers need to work

out strategies to get themselves and their students through such difficulties.

     Primary teachers today are generally four-year trained. They usually do a three or four-year undergraduate

degree, and if this degree does not include teacher training, they will have to undertake postgraduate study in

education as well.

1. After class primary teachers usually _____.

A. come into contact with students

B. teach students a variety of subjects

C. deal with the demands of children

D. make planning, preparation and correction

2. What does the second paragraph mainly discuss?

A. What a primary teacher needs to do in the classroom.

B. The differences between generalist and specialist teaching.

C. How a primary teacher should try his best in the school.

D. The relationship between the primary teachers and students.

3. We can learn from this passage that _____.

A. a primary teacher needs a wide range of skills

B. the disadvantage of primary teaching is having difficult students

C. teacher training is not important for a primary teacher

D. secondary teachers mainly teach children two subjects

4. The author writes the article in order to _____.

A. tell teachers how primary teachers guide students

B. tell teachers what you should do as a primary teacher

C. let readers know more about primary teachers

D. let readers know how to be a primary teacher

单项选择题 案例分析题