Перейти к выбору ответа 01.04.2022Точка C принадлежит отрезку AB. Чему равно расстояние AC , если AB = 48 см, BC — 19 см? Выбрать другой вопрос Смотреть ответ Перейти к выбору ответа Геометрия Вопрос школьника по предмету Геометрия Точка C принадлежит отрезку AB. Чему равно расстояние AC , если AB = 48 см, BC — 19 см? Ответ учителя по предмету Геометрия Ответ: 29см Объяснение:
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acid rains
Every year more and more plants and animals disappear never to be seen
again. Strangely, it is the most intelligent but most thoughtless animal that is
causing most of the problems — man. Nature is very carefully balanced and if
this balance is disturbed, animals can disappear alarmingly fast. Every day,
thousands of species of animals draw closer to extinction. There are countless
number of species which may become extinct before they are even discovered.
In many lakes the fish are dying. Fishermen are worried because every year there
are fewer fish and some lakes have no fish at all. Scientists are beginning to get
worried too. What is killing the fish?
The problem is acid rain. Acid rain is a kind of air pollution. It is caused by
factories that burn coal or oil or gas. These factories send smoke high into the
air. The wind often carries the smoke far from the factories. Some of the
harmful substances in the smoke may come down with the rain hundreds of
miles away.
The rain in many places isn’t natural and clean any more. It’s full of acid
chemicals. When it falls in lakes, it changes them too. The lakes become more
acidic. Acid water is like vinegar or lemon juice. It hurts when it gets in your
eyes. It also kills the plants and animals that usually live in lake water. That is
why the fish are dying in lakes.
But dead fish may be just the beginning of the problem. Scientists are finding
other effects of acid rain. In some large areas trees are dying. Not just one tree
here and there, but whole forests. At first scientists couldn’t understand why.
There were no bugs or diseases in these trees. The weather was not dry. But
now they think that the rain was the cause. Acid rain is making the earth more
acidic in these areas. Some kinds of trees cannot live in the soil that is very
acidic.
Now scientists are also beginning to study the effects of acid rain on larger
animals. For example, they believe that some deer in Poland are less healthy
because of acid rain. If deer are hurt by the rain, what about people? This is the
question many people are beginning to ask. No one knows the answer yet. But
it is an important question for us all.
C+H2SO4=CO2^+SO2^+H2O
Zn+H2SO4=ZNSO4+H2S^+H2O
Cu+H2SO4=CuSO4+SO2^+H2O