Луч света проходит через слой воды в некоторое вещество. Определить абсолютный показатель преломления этого вещества, если скорость

The healthy lifestyle is a healthy nutrition, daily sports and fresh air. All these signs provide a healthy lifestyle. The people playing sports live more long than the contemporaries. The healthy nutrition improves skin and activity of an organism. Fresh air is also useful to an organism.
To be healthy — natural desire of each person. Health — concept not only biological, but also social. Good health — this joyful perception of life, high working capacity. In our country health of each person.
For strengthening of health many procedures are used. For example – water procedure. It protects an organism from various diseases, especially catarrhal. Also solar bathtubs.
In general the person watching over the health has many advantages. He always knows that it is impossible to damage the health. They are higher growth, have the bigger weight and a circle of a thorax, the muscular force and vital capacity of lungs at them is higher. For preservation and maintenance of human health, are important: working conditions, living wage, way of life, condition of health care. All these living conditions of people are defined by a social system of society.

1. on foot
2. on a bus
3. by...
4. on the 8 o`clock train