The clock is a mechanical, electrical or atomic device that measures the passage of time. Mechanical models date from the late Middle Ages. All mechanical models must have a sourse of energy - for example a falling weight or a wound spring. All such models must be carefully regulated to make them run accurately. The energy turns a system of wheels that move the hands.
The computer is based on a microprocessor, a small chip that performs the operation of a central processing unit. The early kinds of computers had a rather small memory, typicaly in the megabyte which is great improvement. Computers has changed peoples lives. We are can not imagine our lives without computers and internet of course.
The laser is generates ,, well organized,, light. The mechanism uses a process known as stimulated emission. It generates electromagnetic radiation in a special microwave region. Nowadays these devices sre widely used in different ways, among which is medicine. The laser is often used to make quick and painless operations.
Hippie is a specific subgroup of the subculture that arose in the U.S. in the early sixties of the twentieth century, which quickly spread to all countries of the world, and virtually disappeared by the mid seventies. In the original hippies were part of the youth movement, which consisted almost entirely of white teenagers and pretty young adults aged between fifteen and twenty-five.
Перевод:
Хиппи это специфическая подгруппа субкультуры, возникшая в США в начале шестидесятых годов двадцатого века, которая быстро распространилась по всем странам мира, и практически исчезла к середине семидесятых. В оригинале хиппи были частью молодежного движения, состоявшего практически полностью из белых тинейджеров и довольно юных взрослых в возрасте от пятнадцати до двадцати пяти.