Химические свойства 2,3 пентандиола (реакции) - №26974112

Химические свойства 2,3 пентандиола (реакции)
- Предмет:
  Химия
- Автор:
  braeden
- 5 лет назад

Ответы 1

.....................................
- Автор:
  omar509
- 5 лет назад
- 0
Добавить свой ответ

Еще вопросы

Срочно!!!
Снаряд массой 10 кг вылетел вверх из пушки со скоростью 500 м./с. Определите потенциальную и кинетическую энергию на высоте 0,3 км
- Предмет:
  Физика
- Автор:
  quintonslhx
- 5 лет назад
- Ответов:
  
  1
- Смотреть
помогите пожалуйста ответить на вопросы по тексту
1. When does water pollution occur?
2. Why do plants and animals require pure water?
3. What are the major water pollutants?
4. How can pollutants be separated?
5. How do petroleum products affect the animals?
6. Why can pesticides and herbicides be dangerous if they penetrate into streams, rivers and
lakes?
7. What do heavy metals result in?
8. How do fertilizers penetrate to water?
9. What damage can thermal pollution cause?
текст
Water pollution occurs mostly, when people overload the water environment such as streams,
lakes, underground water, bays or seas with wastes or substances harmful to living beings.
Water is necessary for life. All organisms contain it, some drink it and some live in it. Plants and
animals require water that is moderately pure, and they cannot survive, if water contains toxic chemicals
or harmful microorganisms. Water pollution kills large quantity of fish, birds, and other animals, in some
cases killing everything in an affected area.
Pollution makes streams, lakes, and coastal waters unpleasant to swim in or to have a rest. Fish
and shellfish harvested from polluted waters may be unsafe to eat. People who use polluted water can
become ill, if they drink polluted water for a long time, it may develop cancer or hurt their future children.
The major water pollutants are chemical, biological, and physical materials that lessen the water
quality. Pollutants can be separated into several different classes:
The first class is petroleum products: oil, fuel, lubrication, plastics. The petroleum products get
into water by accidental spills from ships, tanker trucks and when there are leaks from underground
storage tanks. Many petroleum products are poisonous for animals. Spilled oil damages the feathers of
birds and the fur of animals, often it causes death.
The second class is pesticides and herbicides. There are chemicals used to kill harmful animals
and plants. If they penetrate into streams, rivers, lakes, these chemicals can be very dangerous. The
chemicals can remain dangerous for a long time. When an animal eats a plant that's been treated with it,
the poisons are absorbed into the tissues and organs of the animals.
When other animals feed on a contaminated animal, the chemicals are passed up to them. As it
goes up through the food chain, the chemical becomes more harmful, so animals at the top of the food
chains may suffer cancers, reproductive problems, and death. Nitrates can cause a lethal form of
anaemia in infants.
The third class is heavy metals. They get into the water from industries, automobile exhausts,
mines, and natural soil. Heavy metals also become more harmful as they follow the food chain. They
accumulate in living being's cells and when they reach high levels of concentration in the organism, they
can be extremely poisonous, or can result in long-term health problems. They can sometimes cause liver
and kidney damage.
The fourth class is fertilizers and other nutrients used to promote plant growth on farms and in
gardens.
The fifth class is infectious organisms and pathogens. They enter water through sewage, storm
drains, runoff from farms, etc.
The last one is thermal pollution. Water is often taken from rivers, lakes or seas to be used in
factories and power plants. The water is usually returned to the source warmer than when it was taken.
Even a small temperature change in a body of water can drive away the fish and other species that were
11
originally there, and attract other species in place of them. It breaks a balance and can cause serious
circumstances in future.
- Предмет:
  Английский язык
- Автор:
  higgins16
- 5 лет назад
- Ответов:
  
  1
- Смотреть
Установи соответствие между понятиями и их определениями...

А
сумма расходов на организацию производства товара
Б
последовательность операций (действий), необходимых для изготовления какого-либо продукта
В
превышение доходов от продажи товаров или услуг над затратами на их производство и реализацию
Г
процесс создания различных видов экономического продукта

варианты ответов
1 затраты
2 прибыль
3 технология
4 производство
- Предмет:
  Обществознание
- Автор:
  miniblackwell
- 5 лет назад
- Ответов:
  
  1
- Смотреть
25. Поставьте глаголы, стоящие в скобках, в зависимости от смысла, в Resent Indefinite, Present Continuous, Present Perfect или Present Perfect Continuous;

1. Mary (to learn) French at the University. She (to learn) English since last autumn. 2. They are busy now. They (to discuss) an important question. They (to discuss) it since five clock. 3. Where is John?

– He (to work) in the library. – He (to work) long? – Yes, he (to work) since morning. 4. My son (to be) in hospital. He (to be) there for ten days. 5. Mr. Ivanov (to teach) French. He is a very experienced teacher. He (to teach) French for fifteen years. 6. I (to know) Jack well. – Since when you (to know) him? – I (to know) him since 1980.

26. Переведите на английский язык:

1. Кого вы ждете? – Я жду друга. – Вы давно его ждете? – Да, я жду его уже около получаса. 2. Что вы переводите? – Я перевожу политическую статью. – Как долго вы ее переводите? – Я перевожу ее уже час. 3. Я перевожу восемь или десять статей в неделю. 4. Где мой дневник? – Он лежит на вашем письменном столе. 5. Ваша книга лежит здесь уже несколько дней. Возьмите ее. 6. Мы знаем друг друга очень хорошо. 7. Мы знаем друг друга с тех пор, как я приехал в Петербург. 8. Г-н Браун – директор нашего завода. Он директор завода с 1990 г. 9. Мой брат живет в Омске. – С каких пор он живет там? – Он живет там с 1985 г.
- Предмет:
  Английский язык
- Автор:
  ace54
- 5 лет назад
- Ответов:
  
  0
- Смотреть

How much to ban the user?

1 hour 1 day 100 years