1. To get a constant current, you must have its source. 2. A pyrometer is used to measure the temperature of hot metals. 3. Man learned to dissolve atoms in order to receive a large amount of energy. 4. Scientists are trying to solve the problem associated with new phenomena of electricity. 5. Lightning rod-metal device for protecting buildings from lightning. 6. Carrying out experiments with atmospheric electricity was very dangerous at that time. 7. To magnetize an object is to place it in a magnet field.
Ecology is the study that helps to preserve the Earth, its plants and animals. It is also supposed to study the environment and the relationship between human activities and nature. Until recently this relationship was in balance. However, at present times we have to face such ecological problems as acid rain, global warming, loss of rare species, ozone reduction, etc. Many scientists think that it is connected with industrial boom and development of civilization in the world. Building numerous factories people have started to interfere intensively in nature. Every year world industry pollutes the atmosphere with tons of dust and other harmful things. As a result many species of animals and plants disappear forever, including fish and birds. Many large cities suffer from factory smog. Their activity pollutes the air, the water, the forests and the land. Apart from factories there are lots of vehicles in the streets of every more or less developed city. It includes cars, motorbikes, buses, minivans, trucks and other types of transport which use fuel. First of all, they exhaust toxic gases into the air. Secondly, they are considered to be the main noise offenders in the city. This problem progresses as the number of cars increases from year to year. As a result the level of harmful substances in the air also increases. Another problem which is worth mentioning is the tree cutting. Trees are a source of oxygen and clean air. So, by doing this people simply violate the biological balance. All the above mentioned ecological problems are the result of man’s careless interaction with nature. In my opinion, environmental protection should become of a global concern and serious measures should be taken to create ecological security.
1. To get a constant current, you must have its source. 2. A pyrometer is used to measure the temperature of hot metals. 3. Man learned to dissolve atoms in order to receive a large amount of energy. 4. Scientists are trying to solve the problem associated with new phenomena of electricity. 5. Lightning rod-metal device for protecting buildings from lightning. 6. Carrying out experiments with atmospheric electricity was very dangerous at that time. 7. To magnetize an object is to place it in a magnet field.