1. Work-study program refers to an educational method in which students gain certain economic income and practical experience by participating in various paid or unpaid labor activities during their school days. It aims to help students improve their comprehensive quality, cultivate their practical ability and innovative spirit, and enhance their sense of social responsibility and teamwork spirit.

2. The main forms of work-study programs include on-campus post work, off-campus internship and social service. On-campus job refers to working in various positions within the school, such as librarians, laboratory assistants, campus tour guides, etc. Off-campus practice refers to students' practical activities such as enterprise practice and community service in enterprises, institutions and social organizations.

Time knowledge

1. Time is an indispensable concept in our life. It is the way we perceive and measure the change of things. The related knowledge of time involves the definition, unit, measurement method and application in various fields of time.

2. The definition of time refers to our understanding of the nature and characteristics of time. In physics, time is considered as a measure of the persistence and order of material movement. It is an irreversible physical quantity, that is, time can only flow forward, not backward. In philosophy, the definition of time is more abstract and subjective, and different philosophers have different understandings and explanations of time.

3. Time unit is the standard to measure the length and interval of time. In the International System of Units (SI), the unit of time is the second (S), and the second is the basic unit of time. Other commonly used time units include minutes, hours, days, weeks, months and years. The conversion relationship between these units is fixed, for example, 1 hour equals 60 minutes, and 1 minute equals 60 seconds.

There are many ways to measure time, and the most common one is to use a clock to measure time. Clock is a device for displaying time, which uses mechanical or electronic principles to calculate and display time. Common clocks and watches include mechanical watches, quartz watches and electronic watches. In addition, modern science and technology have developed more accurate and convenient time measuring tools, such as atomic clock and GPS.