2001年6月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices

Production Plans with Multiple Outputs Lety≡(m,,…,ym) be a net output vector, YArn be a convex set,G:Y→R be twice differentiable Production possibility set:{y∈Y|G(y)≤0} Assumption 1.1. Gy (y)>0, Vi,yEY. Proposition 1. 12. Production frontier yEY G(y)=0 contains technologically efficient production plans Definition 1.1. Marginal rate of transformation

The theoretical concepts underlying filtration can be applied towards practical solutions in the field. Comprehension of the basic principles is necessary to select the proper equipment for an application. Theory alone, however, can never be the basis for selection of a filter. Filtration belongs to the physical sciences, and thus conclusions must be based on experimental assay. It is, however, helpful in understanding why a slurry is more suitable for one design of filtration equipment than another

2001年1月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices

When designing a fermenter, one primary consideration is the removal of heat. There is a practical limit to the square feet of cooling surface that can be achieved from a tank jacket and the amount of coils that can be placed inside the tank. The three sources of heat to be removed are from the cooling of media after batch sterilization, from the exothermic fermentation process

2004年6月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked

Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said Both the conversation and the question will be spoken only once. After each question there will be pause. During the pause, you must read the four choices marked), B), C)and D),and

Why search (and cite) the literature of your field? Credibility: To be sure that your work is based on current, sound researchthe-- best in your field. Focus: To be able to place your work in context. Efficiency: To be sure that you're not duplicating work

In the chapter we shall present an introduction to nonlinear circuit analysis and shall examine a few interesting examples of that are used in practice. The principle of analysis will be emphasized. Graphical solution techniques will be given first. In addition, the basic concept of the phase plane shall be considered

1. be able to design a basic experiment in the field of Human-Computer Interaction, where both technological and psychological variables are Lecturer: included,which entails that they shall be able to identify different orientatior thin psychology BoSchenkman be able to apply parts of experimental psychology to Humar Computer Interaction