abide by(=be faithful to ; obey)忠于；遵守。 2. be absent from…. 缺席，不在 3. absence of mind(=being absent-minded) 心不在焉 4. absorb(=take up the attention of)吸引…的注意力(被动语态)be absorbed i n 全神

6.2 Pumping considerations Since the rate of separation depends on the oil globule size it will be appreciated that any disintegration of oil globules in the oily feed to the separator should be avoided and this factor can be seriously affected by the type and rating of the pump used. Tests were carried out by a British government research establishment some years ago on the suitability of various pumps for separator feed duties (Double vane, Triple screw and Single vane )

Directions: In this section, you will hear ten 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 A),),C) and D),and decide which is the best answer

17.1 Introduction 17.2 The mating pathway is triggered by pheromone-receptor interactions 17.3 The mating response activates a G protein 17.4 Yeast can switch silent and active loci for mating type 17.5 The MAT locus codes for regulator proteins 17.6 Silent cassettes at HML and HMR are repressed 17.7 Unidirectional transposition is initiated by the recipient MAT locus 17.8 Regulation of HO expression 17.9 Trypanosomes switch the VSG frequently during infection 17.10 New VSG sequences are generated by gene switching 17.11 VSG genes have an unusual structure 17.12 The bacterial Ti plasmid causes crown gall disease in plants 17.13 T-DNA carries genes required for infection 17.14 Transfer of T-DNA resembles bacterial conjugation 17.15 Selection of amplified genomic sequences 17.16 Transfection introduces exogenous DNA into cells 17.17 Genes can be injected into animal eggs 17.18 ES cells can be incorporated into embryonic mice 17.19 Gene targeting allows genes to be replaced or knocked out

Directions: In this section, you will hear ten 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 A), B), C)and d),and decide which is the best answer. Then mark the corresponding letter on the Answer Sheet with a single line through

Directions: In this section you will hear ten 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 A), B), C)and D), and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through

Directions: In this section you will hear ten 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 A), B), C)and D), and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through

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

Directions: In this section, you will hear ten 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 A), B), C)and d),and decide which is the best answer. Then mark the corresponding letter on the Answer Sheet with a single line through the

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