一定质量的气体，在温度不变的情况下，体积变为原来体积的1/2，则气体的压强变为原来的______倍，气体密度变为原来的______倍．
一定质量的理想气体，在温度不变的情况下，体积变为原来体积的
倍，是等温压缩过程，根据玻意耳定律，有：PV=C，故压强变为原来的2倍；1 2
气体质量不变，体积变为
倍，根据密度定义公式ρ=1 2
，密度变为原来的2倍；m V
故答案为：2，2．
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| With the fast development of society,seeking a job is becoming more and more competitive,thus making it important for people to have career education.And it is suggested that career education should be carried out through one's whole life. Career education is the instruction that is intended to help young people to identify,choose and prepare for a career.Such instruction may focus on a person's role in work,leisure,or family life.Career education differs from vocational education,which is designed to teach specific occupational skills. Career education includes the formal and informal learning that occurs in the family,in the community, and in schools.In schools,career education consists of instructive activities included in many courses. These activities are designed to improve the attitudes,knowledge,and skills that are important for work roles.Career education helps students to develop selfunderstanding and then use it to plan their education and working life. A complete career education program in school begins in kindergarten and continues at least through high school.In kindergartens and elementary schools,youngsters learn about different types of work.In junior middle schools,children begin to explore the occupations and leisure activities that interest them most.In high schools,students get more specific information about occupations and life styles.They may learn how to make career decisions in classrooms,small groups or individual sessions.They also should obtain the skills they need for further study or for a job after graduation.Many colleges and universities also offer career education through their counseling programs.Counselors provide information on such matters as how to locate and apply for jobs and how to be successful in interviews. Teachers and counselors use a variety of methods to provide career education,including films about occupations or industries.Children may invite parents or other adults to come to school and describe their jobs.A student may accompany a worker on his or her job for some time. Both teachers and parents are responsible for youngsters' career education.It really works that students are taught to combine classroom study with practical work experience. Title:Career education-lifelong education
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