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当前学科:中级理化检验技术
题目:
单选题
用气相色谱分析混合物时,各组分的保留时间差异取决于()。
A
各组分在两相间的分配系数
B
柱效
C
检测器的灵敏度
D
记录仪走纸速度
E
柱前压
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Materials and Tools for Language Learning ① The range of materials and tools available to help you with your language studies is huge, from dictionaries to language courses. All of them can help you in different ways, and the appropriate use of these materials and courses will make your language learning much easier and more effective. ② Possibly the most useful tools there are for learning a language are dictionaries. Dictionaries come in a number of formats including bilingual, monolingual, illustrated, electronic and online. Bilingual dictionaries are perhaps the most useful ones for beginners and intermediate learners, while monolingual dictionaries, which are designed for native speakers, are also useful for advanced learners. Pocket dictionaries are good for quick reference and easy to carry around. Larger dictionaries are better if you want more definitions, examples of usage, and information about pronunciation, and grammar. Electronic dictionaries are available as handheld units, or as software. Handheld ones are portable, easy and quick to search, and often provide other functions, such as, text-to-speech, voice recognition and speech synthesis organizers, address books. They tend to be rather expensive though. Software dictionaries offer many of the same functions, and can be used on computers, and mobile phones. ③ The traditional courses tend to consist of textbooks containing dialogues, exercises, notes on grammar, and maybe cultural information. Accompanying cassettes, CDs and/or mp3s are often available. Most such courses are intended for complete beginners or people with only minimal knowledge of the language. Intermediate and advanced-level courses are available for some of the popular languages, such as French, German, Italian and Spanish. ④ Audio courses usually consist solely of cassettes or CDs, though some may also include a limited amount of printed material. All dialogues, exercises, instructions and explanations are recorded and the focus of these courses is teaching you to understand and speak the languages. They are very good at teaching you authentic pronunciation and a manageable amount of vocabulary. ⑤ Various computer-aided courses are available on CD-ROMs and DVDs. Each course is different but they generally include dialogues, audio, exercises and tests. Some also include phrasebooks, dictionaries, videos, games and provide online and/or telephone support. 1.Paragraph①() 2.Paragraph②() 3.Paragraph③() 4.Paragraph④() 5.Paragraph⑤() A. What is the function of audio courses? B. What is the function of flash cards? C. What is the function of traditional courses? D. What are the most useful tools for language learning? E. What is the function of computer-aided courses? F. What can help you a lot with your language learning? 下列选项正确的是()。 The materials and tools available to help you with your language studies range(). The appropriate use of these materials and courses will enable you to learn language() Larger dictionaries will provide the learners with() The traditional courses are designed for() With audio courses, you can learn()
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