Санкт-петербургского государственного университета высшее профессиональное образование т. А. Степанова, И. Ю. Ступина
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| Section II
Упр. 1. Назовите значения следующих интернациональных слов: fundamental, balance, operation, utilize, limitation, intuitive, extreme, delicate, calibration, specialize, actually, visualize, ordinary Упр. 2. Проверьте, помните ли вы значения следующих слов; если нет, обратитесь к словарю: tool, capability, realize, take for granted, precise, ratio, yield, tend, teeter-totter, pendulum, upright, axle Text 34 В Прочтите текст про себя (контрольное время чтения — 2 минуты). Fundamentals of the Analytical Balance O f great importance in the laboratory is the analytical balance, one of the most common laboratory tools. Its usefulness increases when the chcmist understands its operation well enough to utilize the full capabilities and to realize the limitations of the balance. Some chcmistry students do not become proficient in the use of the balance, understandably, they arc concerned with so many other and complex instruments and problems. The balance is taken for granted. It may be that, bccausc balances have been used for so many ccnturics, intuitive knowledge about them is assumed. At the other extreme arc those who know there is something precise and presumably delicatc about a balance, and so they avoid using one if possible. This is unfortunate bccausc mass, along with length and time, is a fundamental measurement. An example is the use o f the balance to prepare standards for the calibration of more specialized instruments. Another important thing about a balancc is its high ratio o f capacity to sensitivity. Few measurements will yield as many significant figures as weighing on an analytical balancc. Results to six significant and cxact figures arc ordinary. Those who have learned about balances by an intuitive proccss tend to think of them as tcctcr-tottcrs. Actually a balancc is a compound pendulum with complications. The essentials of the operation can be understood easily, however, by visualizing an upright wheel free to tum on a fixed axle... Упр. 3. Передайте основное содержание текста в нескольких пред ложениях. Упр. 4. Какое слово в тексте означает «искусный, умелый»? Упр. 5. Найдите в тексте ответы на следующие вопросы: 1. When docs analytical balancc bccomc a useful tool in the laboratory? 2. What is the attitude o f students to the use o f analytical balancc? 3. What measurements arc regarded as fundamental? 4. What is the characteristic feature of analytical balancc? 5. What is the design of the analytical balancc? Упр. б. Закончите следующие предложения: 1. Analytical balancc is... 2. Chemistry students arc conccmcd with... 3. Some students avoid using a balancc bccausc... 4. The balancc can be used to prepare standards for... 5. Usually, a balancc is thought to be... жүктеу/скачать 5,96 Mb. Достарыңызбен бөлісу:
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